Chapter 28b: Separate Compilationlinear-chapter28blinear

Co-authored-by: Hsiang-Ying Fu <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: fuhsnn <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: Symious <14933944+symious@users.noreply.github.com>
Co-authored-by: Jun Kawasaki <jun784@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

55 files changed, 411 insertions, 58 deletions

diff --git a/src/main/java/com/seaofnodes/simple/node/AddNode.java b/src/main/java/com/seaofnodes/simple/node/AddNode.java
index 8835208b..a29ba73b 100644
--- a/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -7,7 +7,7 @@ public class AddNode extends ArithNode {
     @Override boolean allowFloat() { return true; }
     public AddNode(Node lhs, Node rhs) { super(null, lhs, rhs); }
     public AddNode(Node lhs, Node rhs, byte mode) { super(null, lhs, rhs, mode); }
-
+    @Override public Tag serialTag() { return Tag.Add; }
 
     @Override public String label() { return "Add"; }
     @Override public String op() { return "+"; }
diff --git a/src/main/java/com/seaofnodes/simple/node/AndNode.java b/src/main/java/com/seaofnodes/simple/node/AndNode.java
index a737b703..f02007bc 100644
--- a/src/main/java/com/seaofnodes/simple/node/AndNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/AndNode.java
@@ -6,7 +6,7 @@ import com.seaofnodes.simple.type.TypeInteger;
 
 public class AndNode extends ArithNode {
     public AndNode(Parser.Lexer loc, Node lhs, Node rhs) { super(loc, lhs, rhs, (byte)1); }
-
+    @Override public Tag serialTag() { return Tag.And; }
 
     @Override public String op() { return "&"; }
     @Override long doOp( long x, long y ) { return x & y; }
diff --git a/src/main/java/com/seaofnodes/simple/node/ArithNode.java b/src/main/java/com/seaofnodes/simple/node/ArithNode.java
index 094b927f..92ebd587 100644
--- a/src/main/java/com/seaofnodes/simple/node/ArithNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ArithNode.java
@@ -5,6 +5,7 @@ import com.seaofnodes.print.ExprPrinter;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.Utils;
 
 import java.util.HashMap;
@@ -18,7 +19,9 @@ public abstract class ArithNode extends Node implements ModeNode {
 
     public ArithNode( Parser.Lexer loc, Node lhs, Node rhs) { super(null, lhs, rhs); _loc = loc; }
     public ArithNode( Parser.Lexer loc, Node lhs, Node rhs, byte mode) { this(loc,lhs,rhs); _mode=mode; }
-
+    @Override public void packed(BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node,Integer> anodes) {
+        baos.packed1(_mode);
+    }
     abstract String op();
 
     @Override protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) {
diff --git a/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index dd0bc996..73e786e3 100644
--- a/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -5,6 +5,7 @@ import com.seaofnodes.print.ExprPrinter;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.Utils;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -17,7 +18,9 @@ abstract public class BoolNode extends Node implements ModeNode {
 
     public BoolNode(Node lhs, Node rhs) { super(null, lhs, rhs); }
     public BoolNode(Node lhs, Node rhs, byte mode) { super(null, lhs, rhs); _mode = mode; }
-
+    @Override public void packed(BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node,Integer> anodes) {
+        baos.packed1(_mode);
+    }
 
     abstract public String op(); // String opcode name
 
@@ -116,7 +119,7 @@ abstract public class BoolNode extends Node implements ModeNode {
     public static class EQ extends BoolNode {
         public EQ(Node lhs, Node rhs) { super(lhs,rhs); }
         public EQ(Node lhs, Node rhs, byte mode) { super(lhs,rhs, mode); }
-
+        @Override public Tag serialTag() { return Tag.EQ; }
         public String op() { return "=="; }
         TypeInteger doOp(TypeInteger i1, TypeInteger i2) {
             if( i1==i2 && i1.isConstant() ) return TRUE;
@@ -130,7 +133,7 @@ abstract public class BoolNode extends Node implements ModeNode {
     public static class NE extends BoolNode {
         public NE(Node lhs, Node rhs) { super(lhs,rhs); }
         public NE(Node lhs, Node rhs, byte mode) { super(lhs,rhs,mode); }
-
+        @Override public Tag serialTag() { return Tag.NE; }
         public String op() { return "!="; }
         TypeInteger doOp(TypeInteger i1, TypeInteger i2) {
             if( i1==i2 && i1.isConstant() ) return TRUE;
@@ -144,7 +147,7 @@ abstract public class BoolNode extends Node implements ModeNode {
     public static class LT extends BoolNode {
         public LT(Node lhs, Node rhs) { super(lhs,rhs); }
         public LT(Node lhs, Node rhs, byte mode) { super(lhs,rhs, mode); }
-
+        @Override public Tag serialTag() { return Tag.LT; }
         public String op() { return "<" ; }
         TypeInteger doOp(TypeInteger i1, TypeInteger i2) {
             if( i1._max <  i2._min ) return TRUE;
@@ -158,7 +161,7 @@ abstract public class BoolNode extends Node implements ModeNode {
     public static class LE extends BoolNode {
         public LE(Node lhs, Node rhs) { super(lhs,rhs); }
         public LE(Node lhs, Node rhs, byte mode) { super(lhs,rhs,mode); }
-
+        @Override public Tag serialTag() { return Tag.LE; }
         public String op() { return "<="; }
         TypeInteger doOp(TypeInteger i1, TypeInteger i2) {
             if( i1._max <= i2._min ) return TRUE;
@@ -176,7 +179,7 @@ abstract public class BoolNode extends Node implements ModeNode {
             super(lhs,rhs,(byte)1);
             assert mode==1;
         }
-
+        @Override public Tag serialTag() { return Tag.ULT; }
         public String op() { return "u<" ; }
         TypeInteger doOp(TypeInteger i1, TypeInteger i2) {
             if( Long.compareUnsigned(i1._max,i2._min) <  0 ) return TRUE;
diff --git a/src/main/java/com/seaofnodes/simple/node/BulkMemPhiNode.java b/src/main/java/com/seaofnodes/simple/node/BulkMemPhiNode.java
index df9e4fff..c6a6ff3b 100644
--- a/src/main/java/com/seaofnodes/simple/node/BulkMemPhiNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/BulkMemPhiNode.java
@@ -1,8 +1,10 @@
 package com.seaofnodes.simple.node;
 
 import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.codegen.GlobalBits;
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeMem;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.Utils;
 
 import java.util.BitSet;
@@ -44,6 +46,28 @@ public class BulkMemPhiNode extends PhiNode {
 
     public boolean isSplit(int alias) { return _aliases.get(alias); }
 
+    @Override public Tag serialTag() { return Tag.BulkMemPhi; }
+
+    @Override
+    public void packed(BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types,
+                       IdentityHashMap<Node,Integer> anodes) {
+        super.packed(baos,strs,types,anodes);
+        baos.packed2(_aliases.cardinality());
+        for( int alias = _aliases.nextSetBit(0); alias >= 0; alias = _aliases.nextSetBit(alias+1) )
+            baos.packed2(alias);
+    }
+
+    static Node make(BAOS bais, String[] strs, Type[] types, GlobalBits fileAliases, GlobalBits aliases) {
+        Node[] ins = new Node[bais.packed1()];
+        String label = strs[bais.packed2()];
+        BitSet bits = new BitSet();
+        for( int i=bais.packed2(); i>0; i-- ) {
+            int alias = bais.packed2();
+            if( alias >= GlobalBits.RESERVED ) alias = aliases.map(fileAliases,alias);
+            bits.set(alias);
+        }
+        return new BulkMemPhiNode(label,bits.isEmpty() ? EMPTY : bits,ins);
+    }
 
     @Override
     public Type compute() {
diff --git a/src/main/java/com/seaofnodes/simple/node/CLInitNode.java b/src/main/java/com/seaofnodes/simple/node/CLInitNode.java
index 0a0de3cf..7bc17c75 100644
--- a/src/main/java/com/seaofnodes/simple/node/CLInitNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CLInitNode.java
@@ -5,6 +5,7 @@ import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.codegen.CompUnit;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 import java.util.*;
 
 // Track class initializers - the code just after this point expects the named
@@ -22,6 +23,12 @@ public class CLInitNode extends CFGNode implements MultiNode {
         _loc = loc;
     }
 
+    CLInitNode(BAOS bais, String[] strs) { super(null,null,null,null); _loc=Parser.Lexer.unpack(bais,strs); }
+    @Override public Tag serialTag() { return Tag.CLInit; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        Parser.Lexer.packed(_loc,baos,strs);
+    }
+    @Override public void gather(HashMap<String,Integer> strs) { Parser.Lexer.gather(_loc,strs); }
 
     public CLInitNode(CLInitNode init) {
         super(init);
diff --git a/src/main/java/com/seaofnodes/simple/node/CProjNode.java b/src/main/java/com/seaofnodes/simple/node/CProjNode.java
index 2bd48d92..073e4658 100644
--- a/src/main/java/com/seaofnodes/simple/node/CProjNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CProjNode.java
@@ -3,8 +3,10 @@ package com.seaofnodes.simple.node;
 import com.seaofnodes.print.ExprPrinter;
 
 import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.codegen.Serialize;
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeTuple;
+import com.seaofnodes.simple.util.BAOS;
 
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -23,7 +25,14 @@ public class CProjNode extends CFGNode implements Proj {
         _label = label;
     }
     public CProjNode(CProjNode c) { super(c); _idx = c._idx; _label = c._label; }
-
+    @Override public Tag serialTag() { return Tag.CProj; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        baos.packed1(_idx);
+        baos.packed2(_label==null ? 0 : strs.get(_label));
+    }
+    static Node make( BAOS bais, String[] strs ) {
+        return new CProjNode(null, bais.packed1(), strs[bais.packed2()] );
+    }
 
     @Override public String label() { return _label; }
 
@@ -70,4 +79,7 @@ public class CProjNode extends CFGNode implements Proj {
 
     @Override public int idx() { return _idx; }
 
+    @Override public void gather( HashMap<String,Integer> strs ) {
+        Serialize.gather(strs,_label);
+    }
 }
diff --git a/src/main/java/com/seaofnodes/simple/node/CallEndNode.java b/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
index 4422265f..fc6effdc 100644
--- a/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
@@ -5,6 +5,7 @@ import com.seaofnodes.print.ExprPrinter;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -37,7 +38,21 @@ public class CallEndNode extends CFGNode implements MultiNode {
         super(new Node[nIns]);
         _rpc = rpc;
     }
-
+    @Override public Tag serialTag() { return Tag.CallEnd; }
+    public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        baos.packed1(Serialize.nIns(this,anodes));
+        // Linked CallEnds depend on Return types which depend on CallEnds;
+        // break the cycle
+        baos.packed2(types.get(_type));
+        baos.packed2(types.get(_rpc));
+    }
+    static Node make( BAOS bais, Type[] types )  {
+        int nIns = bais.packed1();
+        Type type = types[bais.packed2()];
+        Node cend = new CallEndNode(nIns,(TypeRPC)types[bais.packed2()]);
+        cend._type = type;
+        return cend;
+    }
 
     @Override public boolean blockHead() { return true; }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/CallNode.java b/src/main/java/com/seaofnodes/simple/node/CallNode.java
index f791225a..bcb756fa 100644
--- a/src/main/java/com/seaofnodes/simple/node/CallNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CallNode.java
@@ -9,6 +9,7 @@ import com.seaofnodes.simple.type.TypeFunPtr;
 import com.seaofnodes.simple.type.TypeMem;
 import com.seaofnodes.simple.type.TypeRPC;
 import com.seaofnodes.simple.type.XInt;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.Utils;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -23,7 +24,16 @@ public class CallNode extends CFGNode {
 
     public CallNode(Parser.Lexer loc, Node... nodes) { super(nodes); _loc=loc; CodeGen.CODE._calls.add(this); }
     public CallNode(CallNode call) { super(call); _loc = call._loc; }
-
+    @Override public Tag serialTag() { return Tag.Call; }
+    public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        baos.packed1(nIns());
+        Parser.Lexer.packed(_loc,baos,strs);
+    }
+    @Override public void gather(HashMap<String,Integer> strs) { Parser.Lexer.gather(_loc,strs); }
+    static Node make( BAOS bais, String[] strs ) {
+        int nIns = bais.packed1();
+        return new CallNode(Parser.Lexer.unpack(bais,strs),new Node[nIns]);
+    }
 
     @Override protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) {
         String fname = name();
@@ -44,6 +54,7 @@ public class CallNode extends CFGNode {
     }
 
 
+
     Node ctrl() { return in(0); }
     Node mem () { return in(1); }
     // Args mapped 1-to-1 on inputs, so conceptually start at 2
diff --git a/src/main/java/com/seaofnodes/simple/node/ConFldOffNode.java b/src/main/java/com/seaofnodes/simple/node/ConFldOffNode.java
index 0b8053e2..284220ea 100644
--- a/src/main/java/com/seaofnodes/simple/node/ConFldOffNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ConFldOffNode.java
@@ -21,7 +21,7 @@ public class ConFldOffNode extends ConstantNode {
     public TypeStruct _ts;      // Struct holding field
     public final String _fname; // Field name
     public ConFldOffNode( TypeStruct ts, String fname ) { super(TypeInteger.BOT); _ts = ts; _fname = fname; }
-
+    @Override public Tag serialTag() { throw Utils.TODO("should not reach here"); }
 
     @Override public String label() {
         return _fname == " len" ? "sizeof("+_ts._name+")" : "#"+_fname;
diff --git a/src/main/java/com/seaofnodes/simple/node/ConstantNode.java b/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
index eabf2639..0569f352 100644
--- a/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
@@ -5,6 +5,7 @@ import com.seaofnodes.print.ExprPrinter;
 import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeFunPtr;
+import com.seaofnodes.simple.util.BAOS;
 
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -30,7 +31,11 @@ public class ConstantNode extends TypeNode {
         _type = type;
     }
     public ConstantNode( ConstantNode con ) { super(con); }
-
+    @Override public Tag serialTag() { return Tag.Con; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        baos.packed2(types.get(_con)); // NPE if fails lookup
+    }
+    static Node make( BAOS bais, Type[] types)  { return raw(types[bais.packed2()]); }
 
     // Semantic constant construction through Lower.  A unique internal
     // function identity carries a lifetime edge to the function's Return.
diff --git a/src/main/java/com/seaofnodes/simple/node/CtrlNode.java b/src/main/java/com/seaofnodes/simple/node/CtrlNode.java
index 813e6fcb..62140873 100644
--- a/src/main/java/com/seaofnodes/simple/node/CtrlNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CtrlNode.java
@@ -8,7 +8,7 @@ import com.seaofnodes.simple.type.Type;
 
 public class CtrlNode extends CFGNode {
     public CtrlNode() { super(CodeGen.CODE._start); }
-
+    @Override public Tag serialTag() { throw com.seaofnodes.simple.util.Utils.TODO(); }
     @Override public String label() { return "Ctrl"; }
     @Override protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) { return p.p("Cctrl"); }
     @Override public boolean isConst() { return true; }
diff --git a/src/main/java/com/seaofnodes/simple/node/DivNode.java b/src/main/java/com/seaofnodes/simple/node/DivNode.java
index 0db2b7a2..f173f0ef 100644
--- a/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -9,7 +9,7 @@ public class DivNode extends ArithNode {
     @Override boolean allowFloat() { return true; }
     public DivNode(Node lhs, Node rhs) { super(null, lhs, rhs); }
     public DivNode(Node lhs, Node rhs, byte mode) { super(null, lhs, rhs, mode); }
-
+    @Override public Tag serialTag() { return Tag.Div; }
 
     @Override public String op() { return _mode==1 ? "//" : "/"; }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/EscapeNode.java b/src/main/java/com/seaofnodes/simple/node/EscapeNode.java
index f7518184..3e95fffb 100644
--- a/src/main/java/com/seaofnodes/simple/node/EscapeNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/EscapeNode.java
@@ -35,6 +35,13 @@ public class EscapeNode extends TypeNode {
     public Node pub () { return in(3); }
     public Field fld() { return (Field)_con; }
 
+    @Override public Tag serialTag() { return Tag.Escape; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        baos.packed2(types.get(_con));
+    }
+    static Node make( BAOS bais, Type[] types)  {
+        return new EscapeNode((Field)types[bais.packed2()], null,null,null);
+    }
 
     @Override
     protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) {
diff --git a/src/main/java/com/seaofnodes/simple/node/ExternNode.java b/src/main/java/com/seaofnodes/simple/node/ExternNode.java
index 2d1dc29f..978298fc 100644
--- a/src/main/java/com/seaofnodes/simple/node/ExternNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ExternNode.java
@@ -1,6 +1,8 @@
 package com.seaofnodes.simple.node;
 
+import com.seaofnodes.simple.codegen.Serialize;
 import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.SB;
 
 import java.util.BitSet;
@@ -17,11 +19,20 @@ public class ExternNode extends ConstantNode {
     // Its lifetime and eventual relocation are carried by the extern symbol
     // and CodeGen's FIDX-to-extern mapping instead.
     public ExternNode(Type t, String ex) { super(t,true); _extern = ex; }
-
+    @Override public Tag serialTag() { return Tag.Extern; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        baos.packed2(types.get(_con   ));
+        baos.packed2( strs.get(_extern));
+    }
+    static Node make( BAOS bais, String[] strs, Type[] types)  {
+        return new ExternNode(types[bais.packed2()], strs[bais.packed2()]);
+    }
 
     @Override public String  label() { return "#"+_con+":"+_extern; }
 
     @Override public boolean eq(Node n) { return this==n; }
-
+    @Override public void gather( HashMap<String,Integer> strs ) {
+        Serialize.gather(strs,_extern);
+    }
 
 }
diff --git a/src/main/java/com/seaofnodes/simple/node/ExternOffsetNode.java b/src/main/java/com/seaofnodes/simple/node/ExternOffsetNode.java
index 23ed5468..409ce5d1 100644
--- a/src/main/java/com/seaofnodes/simple/node/ExternOffsetNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ExternOffsetNode.java
@@ -2,6 +2,7 @@ package com.seaofnodes.simple.node;
 
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeInteger;
+import com.seaofnodes.simple.util.BAOS;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
 
@@ -10,7 +11,9 @@ import java.util.IdentityHashMap;
 // selection replaces it with this symbol's address and a zero displacement.
 public class ExternOffsetNode extends ExternNode {
     public ExternOffsetNode(String name) { super(TypeInteger.BOT,name); }
-
+    @Override public Tag serialTag() { return Tag.ExternOffset; }
     @Override public Node copy() { return new ExternOffsetNode(_extern); }
-
+    @Override public void packed(BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node,Integer> nodes) {
+        baos.packed2(strs.get(_extern));
+    }
 }
diff --git a/src/main/java/com/seaofnodes/simple/node/FldOffNode.java b/src/main/java/com/seaofnodes/simple/node/FldOffNode.java
index 535241a6..a9f8d692 100644
--- a/src/main/java/com/seaofnodes/simple/node/FldOffNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/FldOffNode.java
@@ -19,7 +19,7 @@ public class FldOffNode extends TypeNode {
     public final String _fname; // Field name
     public final Parser.Lexer _loc;   //
     public FldOffNode( Node base, String fname, Parser.Lexer loc ) { super(TypeInteger.BOT,base); _fname = fname; _loc=loc; }
-
+    @Override public Tag serialTag() { throw Utils.TODO("should not reach here"); }
 
     @Override public String label() {
         return _fname == " len" ? "sizeof()" : "#"+_fname;
diff --git a/src/main/java/com/seaofnodes/simple/node/FunNode.java b/src/main/java/com/seaofnodes/simple/node/FunNode.java
index ad79130e..edde247a 100644
--- a/src/main/java/com/seaofnodes/simple/node/FunNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/FunNode.java
@@ -3,6 +3,7 @@ package com.seaofnodes.simple.node;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.SB;
 import com.seaofnodes.simple.util.Utils;
 import java.util.Arrays;
@@ -41,7 +42,24 @@ public class FunNode extends RegionNode {
         _compunit = fun._compunit;
         _extern = fun._extern;
     }
-
+    @Override public Tag serialTag() { return Tag.Fun; }
+    @Override public void packed(BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node,Integer> anodes ) {
+        assert !_folding;
+        baos.packed1(Serialize.nIns(this,anodes)); // Object-local linked calls
+        baos.packed2(types.get(_sig)); // NPE if fails lookup
+        baos.packed2(_name==null ? 0 : strs.get(_name));
+        baos.packed2(_approxUIDs);
+        // _compunit set from context on loading, do not write
+    }
+    static Node make( BAOS bais, String[] strs, Type[] types)  {
+        Node[] ins = new Node[bais.packed1()];
+        TypeFunPtr sig = (TypeFunPtr)types[bais.packed2()];
+        String name = strs[bais.packed2()];
+        FunNode fun = new FunNode(null,sig,name,null,ins);
+        fun._approxUIDs = bais.packed2();
+        // _compunit set from context on loading, do not read
+        return fun;
+    }
 
     @Override public String label() { return _name == null ? "$fun"+_sig.fidx() : _name; }
 
@@ -460,4 +478,7 @@ public class FunNode extends RegionNode {
         return slotRotate*8;
     }
 
+    @Override public void gather( HashMap<String,Integer> strs ) {
+        Serialize.gather(strs,_name);
+    }
 }
diff --git a/src/main/java/com/seaofnodes/simple/node/FunPtrNode.java b/src/main/java/com/seaofnodes/simple/node/FunPtrNode.java
index 3d6031b8..82053fd8 100644
--- a/src/main/java/com/seaofnodes/simple/node/FunPtrNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/FunPtrNode.java
@@ -4,6 +4,7 @@ import com.seaofnodes.print.ExprPrinter;
 
 import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -14,8 +15,13 @@ public class FunPtrNode extends TypeNode {
         super(tfp,start,ret);
     }
     public FunPtrNode(FunPtrNode fptr) { super(fptr); }
-
-
+    @Override public Tag serialTag() { return Tag.FunPtr; }
+    @Override public void packed(BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node,Integer> anodes) {
+        baos.packed2(types.get(_con));
+    }
+    static Node make(BAOS bais, Type[] types) {
+        return new FunPtrNode((TypeFunPtr)types[bais.packed2()],null,null);
+    }
     public ReturnNode ret() { return (ReturnNode)in(1); }
     public FunNode fun() { return ret().fun(); }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/GuardNode.java b/src/main/java/com/seaofnodes/simple/node/GuardNode.java
index e985da72..0ce504d9 100644
--- a/src/main/java/com/seaofnodes/simple/node/GuardNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/GuardNode.java
@@ -4,6 +4,7 @@ import com.seaofnodes.print.ExprPrinter;
 
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeScalar;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.Utils;
 
 import java.util.HashMap;
@@ -24,6 +25,11 @@ public class GuardNode extends Node {
         _nonZero = guard._nonZero;
     }
 
+    @Override public Tag serialTag() { return Tag.Guard; }
+    @Override public void packed(BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node,Integer> anodes) {
+        baos.write(_nonZero ? 1 : 0);
+    }
+    static Node make(BAOS bais) { return new GuardNode(bais.read()!=0,null,null); }
 
     @Override public String label() { return _nonZero ? "(!=0)" : "(==0)"; }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/IfNode.java b/src/main/java/com/seaofnodes/simple/node/IfNode.java
index 471a28fe..c83c81d0 100644
--- a/src/main/java/com/seaofnodes/simple/node/IfNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/IfNode.java
@@ -13,7 +13,7 @@ public class IfNode extends CFGNode implements MultiNode {
         CodeGen.CODE.add(this); // Because idoms are complex, just add it
     }
     public IfNode(IfNode iff) { super(iff); }
-
+    @Override public Tag serialTag() { return Tag.If; }
 
     @Override
     protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) {
diff --git a/src/main/java/com/seaofnodes/simple/node/LoadNode.java b/src/main/java/com/seaofnodes/simple/node/LoadNode.java
index e1a495ad..c58bba39 100644
--- a/src/main/java/com/seaofnodes/simple/node/LoadNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/LoadNode.java
@@ -4,7 +4,9 @@ import com.seaofnodes.print.ExprPrinter;
 
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.codegen.GlobalBits;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.Utils;
 import java.util.BitSet;
 
@@ -25,7 +27,11 @@ public class LoadNode extends MemOpNode {
     public LoadNode(Parser.Lexer loc, String name, int alias, Node ctrl, Node mem, Node ptr, Node off) {
         super(loc, name, alias, true, Type.BOTTOM, ctrl, mem, ptr, off);
     }
-
+    LoadNode( BAOS bais, String[] strs, Type[] types, GlobalBits fileAliases, GlobalBits aliases ) {
+        super(bais,strs,types,fileAliases,aliases,true);
+        _con = Type.BOTTOM;      // Serialized slot retained while MemOps share TypeNode
+    }
+    @Override public Tag serialTag() { return Tag.Load; }
 
     @Override boolean canDrop(MemOpNode other, Node dep) {
         return super.canDrop(other,dep) && !clobbered(dep);
diff --git a/src/main/java/com/seaofnodes/simple/node/LoopNode.java b/src/main/java/com/seaofnodes/simple/node/LoopNode.java
index 005a6624..df686bcf 100644
--- a/src/main/java/com/seaofnodes/simple/node/LoopNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/LoopNode.java
@@ -4,6 +4,7 @@ import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeMem;
+import com.seaofnodes.simple.util.BAOS;
 
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -11,7 +12,8 @@ import java.util.IdentityHashMap;
 public class LoopNode extends RegionNode {
     public LoopNode( Parser.Lexer loc, Node xctrl, Node entry ) { super(loc,xctrl,entry,null); }
     public LoopNode( LoopNode loop ) { super(loop); }
-
+    @Override public Tag serialTag() { return Tag.Loop; }
+    public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) { }
 
     public CFGNode entry() { return cfg(1); }
     public CFGNode back () { return cfg(2); }
diff --git a/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java b/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
index cbf19c55..dfe8794d 100644
--- a/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
@@ -4,6 +4,7 @@ import com.seaofnodes.print.ExprPrinter;
 
 import com.seaofnodes.simple.*;
 import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.type.*;
 import com.seaofnodes.simple.util.Utils;
 
@@ -17,7 +18,9 @@ public class MemMergeNode extends Node {
 
     public MemMergeNode( Node ...nodes) { super(nodes); _type = TypeMem.BOT; }
     public MemMergeNode(MemMergeNode mem) { super(mem); }
-
+    @Override public Tag serialTag() { return Tag.MemMerge; }
+    public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) { baos.packed1(nIns()); }
+    static Node make( BAOS bais )  { Node mem = new MemMergeNode(); mem.setDefX(bais.packed1()-1,null); return mem; }
 
     @Override public String label() { return "ALLMEM"; }
     @Override public boolean isMem() { return true; }
diff --git a/src/main/java/com/seaofnodes/simple/node/MemOpNode.java b/src/main/java/com/seaofnodes/simple/node/MemOpNode.java
index fa399e1d..bfbd46c3 100644
--- a/src/main/java/com/seaofnodes/simple/node/MemOpNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/MemOpNode.java
@@ -4,6 +4,7 @@ import com.seaofnodes.print.ExprPrinter;
 
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.codegen.GlobalBits;
 import com.seaofnodes.simple.type.*;
 import com.seaofnodes.simple.util.*;
 import java.lang.StringBuilder;
@@ -60,6 +61,24 @@ public abstract class MemOpNode extends TypeNode {
         _isLoad= mop._isLoad;
     }
 
+    MemOpNode( BAOS bais, String[] strs, Type[] types, GlobalBits fileAliases, GlobalBits aliases, boolean isLoad ) {
+        this(null,
+             strs[bais.packed2()],
+             mapAlias(bais,fileAliases,aliases),isLoad,
+             types[bais.packed2()],null,null,null,null);
+    }
+
+    private static int mapAlias( BAOS bais, GlobalBits fileAliases, GlobalBits aliases ) {
+        int alias = bais.packed2();
+        return alias < GlobalBits.RESERVED ? alias : aliases.map(fileAliases,alias);
+    }
+
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        baos.packed2(_name==null ? 0 : strs.get(_name));
+        baos.packed2(_alias);
+        baos.packed2(types.get(_con));                // NPE if fails lookup
+        assert _isLoad == this instanceof LoadNode; // No machine ops
+    }
 
     static String mlabel(String name) { return "[]"==name ? "ary" : ("#"==name ? "len" : name); }
     String mlabel() { return mlabel(_name); }
diff --git a/src/main/java/com/seaofnodes/simple/node/MemPhiNode.java b/src/main/java/com/seaofnodes/simple/node/MemPhiNode.java
index 5ae716a7..aaaedb89 100644
--- a/src/main/java/com/seaofnodes/simple/node/MemPhiNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/MemPhiNode.java
@@ -2,6 +2,8 @@ package com.seaofnodes.simple.node;
 
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeMem;
+import com.seaofnodes.simple.codegen.GlobalBits;
+import com.seaofnodes.simple.util.BAOS;
 
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -22,6 +24,22 @@ public class MemPhiNode extends PhiNode {
         _alias = phi._alias;
     }
 
+    @Override public Tag serialTag() { return Tag.MemPhi; }
+
+    @Override
+    public void packed(BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types,
+                       IdentityHashMap<Node,Integer> anodes) {
+        super.packed(baos,strs,types,anodes);
+        baos.packed2(_alias);
+    }
+
+    static Node make(BAOS bais, String[] strs, Type[] types, GlobalBits fileAliases, GlobalBits aliases) {
+        Node[] ins = new Node[bais.packed1()];
+        String label = strs[bais.packed2()];
+        int alias = bais.packed2();
+        if( alias >= GlobalBits.RESERVED ) alias = aliases.map(fileAliases,alias);
+        return new MemPhiNode(label,alias,ins);
+    }
 
     @Override
     public Type compute() {
diff --git a/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index 4d7e3ddb..e84eb611 100644
--- a/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -4,6 +4,7 @@ package com.seaofnodes.simple.node;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.Utils;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -14,7 +15,10 @@ public class MinusNode extends Node implements ModeNode {
 
     public MinusNode(Node in) { super(null, in); }
     public MinusNode(Node in, byte mode) { super(null, in); _mode = mode; }
-
+    @Override public void packed(BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node,Integer> anodes) {
+        baos.packed1(_mode);
+    }
+    @Override public Tag serialTag() { return Tag.Minus; }
 
     @Override public byte mode() { return _mode; }
     @Override public Node setMode(byte mode) {
diff --git a/src/main/java/com/seaofnodes/simple/node/MulNode.java b/src/main/java/com/seaofnodes/simple/node/MulNode.java
index 49c6432a..bb99cad5 100644
--- a/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -9,7 +9,7 @@ public class MulNode extends ArithNode {
     @Override boolean allowFloat() { return true; }
     public MulNode(Node lhs, Node rhs) { super(null, lhs, rhs); }
     public MulNode(Node lhs, Node rhs, byte mode) { super(null, lhs, rhs, mode); }
-
+    @Override public Tag serialTag() { return Tag.Mul; }
 
     @Override public String op() { return "*"; }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/NeverNode.java b/src/main/java/com/seaofnodes/simple/node/NeverNode.java
index a7b4cf65..ba1dab8c 100644
--- a/src/main/java/com/seaofnodes/simple/node/NeverNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/NeverNode.java
@@ -12,7 +12,7 @@ import com.seaofnodes.simple.type.TypeTuple;
 public class NeverNode extends IfNode {
     public NeverNode(NeverNode ctrl) { super(ctrl); }
     public NeverNode(float ignore, Node ctrl) { super(ctrl,null); }
-
+    @Override public Tag serialTag() { return Tag.Never; }
 
     @Override public String label() { return "Never"; }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/NewNode.java b/src/main/java/com/seaofnodes/simple/node/NewNode.java
index 5cbe1b61..fe80f690 100644
--- a/src/main/java/com/seaofnodes/simple/node/NewNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/NewNode.java
@@ -4,6 +4,7 @@ import com.seaofnodes.print.ExprPrinter;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.SB;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -22,7 +23,14 @@ public class NewNode extends Node implements MultiNode {
 
     // --- Serialization
     public NewNode(NewNode nnn) { super(nnn); _ts = nnn._ts; }
-
+    @Override public Tag serialTag() { return Tag.New; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        baos.packed2(types.get(_ts));
+    }
+    static Node make( BAOS bais, Type[] types)  {
+        TypeStruct ts = (TypeStruct)types[bais.packed2()];
+        return new NewNode(ts,null,null);
+    }
 
     @Override public String label() { return "new_"+(_ts.isAry() ? "ary_"+_ts._fields[1]._t.str() : _ts.str()); }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/Node.java b/src/main/java/com/seaofnodes/simple/node/Node.java
index de39ca80..8718f351 100644
--- a/src/main/java/com/seaofnodes/simple/node/Node.java
+++ b/src/main/java/com/seaofnodes/simple/node/Node.java
@@ -5,6 +5,7 @@ import com.seaofnodes.print.BaseNode;
 import com.seaofnodes.simple.IterPeeps;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.codegen.GlobalBits;
 import com.seaofnodes.simple.print.IRPrinter;
 import com.seaofnodes.simple.type.*;
 import com.seaofnodes.simple.util.*;
@@ -67,8 +68,84 @@ public abstract class Node extends BaseNode<Node> implements Cloneable {
         _hash = 0;
     }
 
+    // Disk/serialized opcode tags
+    public enum Tag {
+        Add,And,BulkMemPhi,EQ,NE,LT,LE,ULT,
+        CallEnd,Call,ConFldOff,Con,CLInit,CProj,
+        Div,Escape,Extern,ExternOffset,Fun,FunPtr,Guard,
+        If,Load,Loop,MemMerge,MemPhi,Minus,Mul,
+        New,Never,Not,Or,Parm,Phi,Proj,PtrToInt,
+        ReadOnly,Return,Region,RoundF32,
+        Sar,Shl,Shr,Start,StartCU,StopCU,Stop,Store,Sub,
+        ToInteger,ToFloat,XCtrl,Xor;
+        public static final Tag[] VALS = values();
+        public Node make( BAOS bais, String[] strs, Type[] types, GlobalBits fileAliases, GlobalBits aliases ) {
+            return switch(this) {
+            case Add    -> new   AddNode(null,null,(byte)bais.packed1());
+            case And    -> { int mode=bais.packed1(); assert mode==1; yield new AndNode(null,null,null); }
+            case Div    -> new   DivNode(null,null,(byte)bais.packed1());
+            case Guard -> GuardNode.make(bais);
+            case If     -> new    IfNode(null,null);
+            case Loop   -> new  LoopNode(null,null,null);
+            case Minus  -> new MinusNode(null,(byte)bais.packed1());
+            case Mul    -> new   MulNode(null,null,(byte)bais.packed1());
+            case Never  -> new NeverNode(1.2f, null);
+            case Not    -> new   NotNode(null);
+            case Or     -> { int mode=bais.packed1(); assert mode==1; yield new OrNode(null,null,null); }
+            case ReadOnly-> new ReadOnlyNode((Node)null);
+            case Return ->new ReturnNode(null,null,null,null,null);
+            case RoundF32-> new RoundF32Node(null);
+            case PtrToInt-> new PtrToIntNode((Node)null);
+            case Sar    -> { int mode=bais.packed1(); assert mode==1; yield new SarNode(null,null,null); }
+            case Shl    -> { int mode=bais.packed1(); assert mode==1; yield new ShlNode(null,null,null); }
+            case Shr    -> { int mode=bais.packed1(); assert mode==1; yield new ShrNode(null,null,null); }
+            case Start  -> new StartNode(null,null,TypeInteger.BOT);
+            case Sub    -> new   SubNode(null,null,(byte)bais.packed1());
+            case ToFloat-> new ToFloatNode(null);
+            case ToInteger-> new ToIntegerNode(null);
+            case XCtrl  -> new XCtrlNode();
+            case Xor    -> { int mode=bais.packed1(); assert mode==1; yield new XorNode(null,null,null); }
+
+            case EQ    -> new  BoolNode.EQ (null,null,(byte)bais.packed1());
+            case NE    -> new  BoolNode.NE (null,null,(byte)bais.packed1());
+            case LT    -> new  BoolNode.LT (null,null,(byte)bais.packed1());
+            case LE    -> new  BoolNode.LE (null,null,(byte)bais.packed1());
+            case ULT   -> new  BoolNode.ULT(null,null,(byte)bais.packed1());
+
+            case Call  ->      CallNode.make(bais,strs);
+            case CallEnd->  CallEndNode.make(bais     ,types);
+            case CLInit ->    new CLInitNode(bais,strs);
+            case CProj ->     CProjNode.make(bais,strs);
+            case Con   ->  ConstantNode.make(bais     ,types);
+            case Escape->    EscapeNode.make(bais     ,types);
+            case Extern->    ExternNode.make(bais,strs,types);
+            case ExternOffset-> new ExternOffsetNode(strs[bais.packed2()]);
+            case FunPtr->    FunPtrNode.make(bais,     types);
+            case Fun   ->       FunNode.make(bais,strs,types);
+            case Load  ->       new LoadNode(bais,strs,types,fileAliases,aliases);
+            case MemMerge->MemMergeNode.make(bais);
+            case MemPhi->    MemPhiNode.make(bais,strs,types,fileAliases,aliases);
+            case BulkMemPhi-> BulkMemPhiNode.make(bais,strs,types,fileAliases,aliases);
+            case New   ->       NewNode.make(bais     ,types);
+            case Parm  ->      ParmNode.make(bais,strs,types);
+            case Phi   ->       PhiNode.make(bais,strs,types);
+            case Proj  ->      ProjNode.make(bais,strs);
+            case Store ->      new StoreNode(bais,strs,types,fileAliases,aliases);
+            case Stop  ->      StopNode.make(bais);
+            case StartCU->  StartCUNode.make(bais,strs,types);
+            case StopCU ->   StopCUNode.make(bais);
+            case Region->    RegionNode.make(bais);
+
+            default -> throw Utils.TODO("Should not reach here");
+            };
+        }
+    };
+    public Tag serialTag() { throw Utils.TODO(); }
+    // Serialize extra data, including input counts
+    public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {}
+
     // Easy reading label for debugger, e.g. "Add" or "Region" or "EQ"
-    public String label() { return getClass().getSimpleName().replace("Node",""); }
+    public String label() { return serialTag().toString(); }
 
     public String p(int depth) { return IRPrinter.prettyPrint(this,depth); }
 
@@ -667,6 +744,7 @@ public abstract class Node extends BaseNode<Node> implements Cloneable {
         return null;
     }
 
+    public void gather(HashMap<String,Integer> strs ) { }
 
     // If a Type upgrade happens, put on worklist
     boolean _upgradeType( HashMap<String,Type> TYPES ) { return false; }
diff --git a/src/main/java/com/seaofnodes/simple/node/NotNode.java b/src/main/java/com/seaofnodes/simple/node/NotNode.java
index e22d16b6..2328c287 100644
--- a/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -6,7 +6,7 @@ import com.seaofnodes.simple.util.Utils;
 
 public class NotNode extends Node {
     public NotNode(Node in) { super(null, in); }
-
+    @Override public Tag serialTag() { return Tag.Not; }
 
     @Override protected String format() { return "(!%1)"; }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/OrNode.java b/src/main/java/com/seaofnodes/simple/node/OrNode.java
index 263c3e87..9d50d1a9 100644
--- a/src/main/java/com/seaofnodes/simple/node/OrNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/OrNode.java
@@ -6,7 +6,7 @@ import com.seaofnodes.simple.type.TypeInteger;
 
 public class OrNode extends ArithNode {
     public OrNode( Parser.Lexer loc, Node lhs, Node rhs) { super(loc,lhs, rhs, (byte)1); }
-
+    @Override public Tag serialTag() { return Tag.Or; }
 
     @Override public String label() { return "Or"; }
     @Override public String op() { return "|"; }
diff --git a/src/main/java/com/seaofnodes/simple/node/ParmNode.java b/src/main/java/com/seaofnodes/simple/node/ParmNode.java
index 316efb93..91c471c0 100644
--- a/src/main/java/com/seaofnodes/simple/node/ParmNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ParmNode.java
@@ -3,6 +3,8 @@ package com.seaofnodes.simple.node;
 import com.seaofnodes.print.ExprPrinter;
 
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.codegen.Serialize;
+import com.seaofnodes.simple.util.BAOS;
 
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -20,7 +22,19 @@ public class ParmNode extends PhiNode {
         _type = declaredType;
     }
     public ParmNode(ParmNode parm) { super(parm, parm._label ); _idx = parm._idx; _declaredType = parm._declaredType; }
-
+    @Override public Tag serialTag() { return Tag.Parm; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        baos.packed1(Serialize.nIns(this,anodes)); // Object-local linked calls
+        baos.packed2(_label==null ? 0 : strs.get(_label));
+        baos.packed2(types.get(_declaredType)); // NPE if fails lookup
+        baos.packed1(_idx);
+    }
+    static Node make( BAOS bais, String[] strs, Type[] types)  {
+        Node[] ins = new Node[bais.packed1()];
+        String label =   strs[bais.packed2()];
+        Type minType =  types[bais.packed2()];
+        return new ParmNode(label, bais.packed1(), minType, ins);
+    }
 
     @Override public String label() { return MemOpNode.mlabel(_label); }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/PhiNode.java b/src/main/java/com/seaofnodes/simple/node/PhiNode.java
index 61e4b468..3cf6f854 100644
--- a/src/main/java/com/seaofnodes/simple/node/PhiNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/PhiNode.java
@@ -3,6 +3,7 @@ package com.seaofnodes.simple.node;
 import com.seaofnodes.print.ExprPrinter;
 
 import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.codegen.Serialize;
 import com.seaofnodes.simple.type.*;
 import com.seaofnodes.simple.util.*;
 import java.util.HashMap;
@@ -35,7 +36,15 @@ public class PhiNode extends Node {
         while( nIns() < r.nIns() )
             addDef(sample);
     }
-
+    @Override public Tag serialTag() { return Tag.Phi; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        baos.packed1(nIns());
+        baos.packed2(_label==null ? 0 : strs.get(_label));
+    }
+    static Node make( BAOS bais, String[] strs, Type[] types)  {
+        Node[] ins = new Node[bais.packed1()];
+        return new PhiNode(strs[bais.packed2()], ins);
+    }
 
     @Override public String label() { return "Phi_"+MemOpNode.mlabel(_label); }
 
@@ -272,4 +281,7 @@ public class PhiNode extends Node {
         return Parser.error(sb.unchar(5).toString(),null);
     }
 
+    @Override public void gather( HashMap<String,Integer> strs ) {
+        Serialize.gather(strs,_label);
+    }
 }
diff --git a/src/main/java/com/seaofnodes/simple/node/ProjNode.java b/src/main/java/com/seaofnodes/simple/node/ProjNode.java
index a0142379..fcc113a8 100644
--- a/src/main/java/com/seaofnodes/simple/node/ProjNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ProjNode.java
@@ -2,9 +2,11 @@ package com.seaofnodes.simple.node;
 
 import com.seaofnodes.print.ExprPrinter;
 
+import com.seaofnodes.simple.codegen.Serialize;
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeMem;
 import com.seaofnodes.simple.type.TypeTuple;
+import com.seaofnodes.simple.util.BAOS;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
 
@@ -22,7 +24,14 @@ public class ProjNode extends Node implements Proj {
         _label = label;
     }
     public ProjNode(ProjNode p) { super(p); _idx = p._idx; _label = p._label; }
-
+    @Override public Tag serialTag() { return Tag.Proj; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        baos.packed1(_idx);
+        baos.packed2(_label==null ? 0 : strs.get(_label));
+    }
+    static Node make( BAOS bais, String[] strs )  {
+        return new ProjNode(null, bais.packed1(), strs[bais.packed2()] );
+    }
 
     @Override public String label() { return _label; }
 
@@ -56,4 +65,7 @@ public class ProjNode extends Node implements Proj {
 
     @Override public int idx() { return _idx; }
 
+    @Override public void gather( HashMap<String,Integer> strs ) {
+        Serialize.gather(strs,_label);
+    }
 }
diff --git a/src/main/java/com/seaofnodes/simple/node/PtrToIntNode.java b/src/main/java/com/seaofnodes/simple/node/PtrToIntNode.java
index 094734fa..d3d38060 100644
--- a/src/main/java/com/seaofnodes/simple/node/PtrToIntNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/PtrToIntNode.java
@@ -18,7 +18,7 @@ public class PtrToIntNode extends Node {
     public PtrToIntNode(Node ptr) { super(null,ptr); }
     public PtrToIntNode(PtrToIntNode ptr) { super(ptr); }
 
-
+    @Override public Tag serialTag() { return Tag.PtrToInt; }
     @Override protected String format() { return "(i64*)%1"; }
 
     @Override public Type compute() {
diff --git a/src/main/java/com/seaofnodes/simple/node/ReadOnlyNode.java b/src/main/java/com/seaofnodes/simple/node/ReadOnlyNode.java
index ab7e0ae0..0a720d5b 100644
--- a/src/main/java/com/seaofnodes/simple/node/ReadOnlyNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ReadOnlyNode.java
@@ -10,7 +10,7 @@ import com.seaofnodes.simple.type.TypeMemPtr;
 public class ReadOnlyNode extends Node {
     public ReadOnlyNode( Node n ) { super(null,n); }
     public ReadOnlyNode( ReadOnlyNode n ) { super(n); }
-
+    @Override public Tag serialTag() { return Tag.ReadOnly; }
 
     @Override protected String format() { return "(const)%1"; }
     @Override public Type compute() {
diff --git a/src/main/java/com/seaofnodes/simple/node/RegionNode.java b/src/main/java/com/seaofnodes/simple/node/RegionNode.java
index 923773c4..8883ba8e 100644
--- a/src/main/java/com/seaofnodes/simple/node/RegionNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/RegionNode.java
@@ -5,6 +5,7 @@ import com.seaofnodes.print.ExprPrinter;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.util.BAOS;
 import java.util.*;
 
 public class RegionNode extends CFGNode {
@@ -14,7 +15,9 @@ public class RegionNode extends CFGNode {
     public RegionNode(Parser.Lexer loc, Node...   nodes) { super(nodes); _loc = loc; }
     public RegionNode(RegionNode r, Parser.Lexer loc) { super(r); _loc = loc; }
     public RegionNode(RegionNode r) { super(r); if( r!=null ) _loc = r._loc; }
-
+    @Override public Tag serialTag() { return Tag.Region; }
+    public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) { baos.packed1(nIns()); }
+    static Node make( BAOS bais ) { return new RegionNode(null,new Node[bais.packed1()]); }
 
     @Override protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) {
         return p.p(label());
diff --git a/src/main/java/com/seaofnodes/simple/node/ReturnNode.java b/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
index 0bb090ee..0431f7d5 100644
--- a/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
@@ -28,7 +28,7 @@ public class ReturnNode extends CFGNode {
         _fun = fun;
     }
     public ReturnNode( ReturnNode ret, FunNode fun ) { super(ret);  _fun = fun;  }
-
+    @Override public Tag serialTag() { return Tag.Return; }
 
     public Node ctrl() { return in(0); }
     public Node mem () { return in(1); }
diff --git a/src/main/java/com/seaofnodes/simple/node/RoundF32Node.java b/src/main/java/com/seaofnodes/simple/node/RoundF32Node.java
index 02d3bbaa..65f10a79 100644
--- a/src/main/java/com/seaofnodes/simple/node/RoundF32Node.java
+++ b/src/main/java/com/seaofnodes/simple/node/RoundF32Node.java
@@ -7,7 +7,7 @@ import com.seaofnodes.simple.type.TypeFloat;
 
 public class RoundF32Node extends Node {
     public RoundF32Node(Node lhs) { super(null, lhs); }
-
+    @Override public Tag serialTag() { return Tag.RoundF32; }
 
     @Override protected String format() { return "((f32)%1)"; }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/SarNode.java b/src/main/java/com/seaofnodes/simple/node/SarNode.java
index fa63334b..737b531f 100644
--- a/src/main/java/com/seaofnodes/simple/node/SarNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/SarNode.java
@@ -6,7 +6,7 @@ import com.seaofnodes.simple.type.TypeInteger;
 
 public class SarNode extends ArithNode {
     public SarNode(Parser.Lexer loc, Node lhs, Node rhs) { super(loc, lhs, rhs, (byte)1); }
-
+    @Override public Tag serialTag() { return Tag.Sar; }
 
     @Override public String op() { return ">>"; }
     @Override long doOp( long x, long y ) { return x >> y; }
diff --git a/src/main/java/com/seaofnodes/simple/node/ShlNode.java b/src/main/java/com/seaofnodes/simple/node/ShlNode.java
index 380fc246..f657cf51 100644
--- a/src/main/java/com/seaofnodes/simple/node/ShlNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ShlNode.java
@@ -7,7 +7,7 @@ import com.seaofnodes.simple.type.TypeInteger;
 
 public class ShlNode extends ArithNode {
     public ShlNode(Parser.Lexer loc, Node lhs, Node rhs) { super(loc, lhs, rhs, (byte)1); }
-
+    @Override public Tag serialTag() { return Tag.Shl; }
 
     @Override public String op() { return "<<"; }
     @Override long doOp( long x, long y ) { return x << y; }
diff --git a/src/main/java/com/seaofnodes/simple/node/ShrNode.java b/src/main/java/com/seaofnodes/simple/node/ShrNode.java
index 17170a1f..e93ea0e8 100644
--- a/src/main/java/com/seaofnodes/simple/node/ShrNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ShrNode.java
@@ -6,7 +6,7 @@ import com.seaofnodes.simple.type.TypeInteger;
 
 public class ShrNode extends ArithNode {
     public ShrNode(Parser.Lexer loc, Node lhs, Node rhs) { super(loc, lhs, rhs, (byte)1); }
-
+    @Override public Tag serialTag() { return Tag.Shr; }
 
     @Override public String op() { return ">>>"; }
     @Override long doOp( long x, long y ) { return x >>> y; }
diff --git a/src/main/java/com/seaofnodes/simple/node/StartCUNode.java b/src/main/java/com/seaofnodes/simple/node/StartCUNode.java
index 0f7a322a..cd51f603 100644
--- a/src/main/java/com/seaofnodes/simple/node/StartCUNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/StartCUNode.java
@@ -1,7 +1,9 @@
 package com.seaofnodes.simple.node;
 
 import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.codegen.Serialize;
 import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.util.BAOS;
 
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -11,12 +13,21 @@ public class StartCUNode extends StartNode {
     public final String _fname;
     public StartCUNode(StartNode start, StopCUNode stop, Type arg, String fname) { super(start,stop,arg);  _fname = fname;  }
     public StartCUNode(StartCUNode start) { super(start); _fname = start._fname; }
-
+    @Override public Tag serialTag() { return Tag.StartCU; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node,Integer> anodes ) {
+        baos.packed2(types.get(_arg));
+        baos.packed2(strs.get(_fname));
+    }
+    static Node make( BAOS bais, String[] strs, Type[] types )  {
+        return new StartCUNode(null,null,types[bais.packed2()],strs[bais.packed2()]);
+    }
 
     @Override public CFGNode cfg0() { return (CFGNode)in(0); }
 
     // IDom is cfg0() and depth is always Start+1 which is 0+1 or 1
     @Override public int idepth() { return 1; }
     @Override public CFGNode idom(Node dep) { return cfg0(); }
-
+    @Override public void gather( HashMap<String,Integer> strs ) {
+        Serialize.gather(strs,_fname);
+    }
 }
diff --git a/src/main/java/com/seaofnodes/simple/node/StartNode.java b/src/main/java/com/seaofnodes/simple/node/StartNode.java
index 3c605e30..495be0a2 100644
--- a/src/main/java/com/seaofnodes/simple/node/StartNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/StartNode.java
@@ -29,7 +29,7 @@ public class StartNode extends LoopNode implements MultiNode {
 
     public StartNode(StartNode start, StopNode stop, Type arg) { super(null,start,stop); _arg = arg;  }
     public StartNode(StartNode start) { super(start); _arg = start==null ? null : start._arg; }
-
+    @Override public Tag serialTag() { return Tag.Start; }
     public Type arg() { return _arg; }
 
     @Override protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) {
diff --git a/src/main/java/com/seaofnodes/simple/node/StopCUNode.java b/src/main/java/com/seaofnodes/simple/node/StopCUNode.java
index 53c2325c..43acf631 100644
--- a/src/main/java/com/seaofnodes/simple/node/StopCUNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/StopCUNode.java
@@ -2,6 +2,7 @@ package com.seaofnodes.simple.node;
 
 import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -10,7 +11,13 @@ import java.util.IdentityHashMap;
 public class StopCUNode extends StopNode {
     public StopCUNode() { super(); }
     public StopCUNode(StopNode stop) { super(stop); }
-
+    @Override public Tag serialTag() { return Tag.StopCU; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) { baos.packed1(nIns()); }
+    static Node make( BAOS bais ) {
+        StopCUNode stop = new StopCUNode();
+        stop.setDefX(bais.packed1()-1,null);
+        return stop;
+    }
 
     public StartCUNode start() {
         for( Node use : _outputs )
diff --git a/src/main/java/com/seaofnodes/simple/node/StopNode.java b/src/main/java/com/seaofnodes/simple/node/StopNode.java
index 7238f1f9..a7e52563 100644
--- a/src/main/java/com/seaofnodes/simple/node/StopNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/StopNode.java
@@ -3,7 +3,9 @@ package com.seaofnodes.simple.node;
 import com.seaofnodes.print.ExprPrinter;
 
 import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.codegen.Serialize;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -16,7 +18,13 @@ public class StopNode extends CFGNode {
         _type = compute();
     }
     public StopNode(StopNode stop) { super(stop); }
-
+    @Override public Tag serialTag() { return Tag.Stop; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) { baos.packed1(Serialize.nIns(this,anodes)); }
+    static Node make( BAOS bais ) {
+        StopNode stop = new StopNode();
+        stop.setDefX(bais.packed1()-1,null);
+        return stop;
+    }
 
     @Override
     protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) {
diff --git a/src/main/java/com/seaofnodes/simple/node/StoreNode.java b/src/main/java/com/seaofnodes/simple/node/StoreNode.java
index bdd07c8d..5fa0b99f 100644
--- a/src/main/java/com/seaofnodes/simple/node/StoreNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/StoreNode.java
@@ -4,7 +4,9 @@ import com.seaofnodes.print.ExprPrinter;
 
 import com.seaofnodes.simple.*;
 import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.codegen.GlobalBits;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.Utils;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
@@ -35,7 +37,18 @@ public class StoreNode extends MemOpNode {
         _init = init;
         _size = size;
     }
-
+    StoreNode( BAOS bais, String[] strs, Type[] types, GlobalBits fileAliases, GlobalBits aliases ) {
+        super(bais,strs,types,fileAliases,aliases,false);
+        addDef(null);
+        _init = bais.read() != 0;
+        _size = (byte)bais.read();
+    }
+    @Override public Tag serialTag() { return Tag.Store; }
+    @Override public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        super.packed(baos,strs,types, anodes );
+        baos.write(_init ? 1 : 0);
+        baos.write(_size);
+    }
 
     @Override boolean canDrop(MemOpNode other, Node dep) {
         return super.canDrop(other,dep) && _init==((StoreNode)other)._init;
@@ -114,7 +127,7 @@ public class StoreNode extends MemOpNode {
         // Freeze the semantic Store variant as soon as the pointer exposes a
         // canonical field declaration.  Waiting until after structural memory
         // peeps can lose the declaration to a flow-sensitive constant field
-        // state.
+        // state.  Imported Stores already carry a serialized non-zero width.
         if( _size==0 && (_size= storageType()) != 0 ) {
             unlock();           // Width participates in the cached hash.
             return init();
diff --git a/src/main/java/com/seaofnodes/simple/node/SubNode.java b/src/main/java/com/seaofnodes/simple/node/SubNode.java
index adad2ed5..8eb1f4cc 100644
--- a/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -9,7 +9,7 @@ public class SubNode extends ArithNode {
     @Override boolean allowFloat() { return true; }
     public SubNode(Node lhs, Node rhs) { super(null, lhs, rhs); }
     public SubNode(Node lhs, Node rhs, byte mode) { super(null, lhs, rhs,mode); }
-
+    @Override public Tag serialTag() { return Tag.Sub; }
 
     @Override public String op() { return "-"; }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/ToFloatNode.java b/src/main/java/com/seaofnodes/simple/node/ToFloatNode.java
index 1acf55b6..151a326e 100644
--- a/src/main/java/com/seaofnodes/simple/node/ToFloatNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ToFloatNode.java
@@ -8,7 +8,7 @@ import com.seaofnodes.simple.type.TypeInteger;
 
 public class ToFloatNode extends Node {
     public ToFloatNode(Node lhs) { super(null, lhs); }
-
+    @Override public Tag serialTag() { return Tag.ToFloat; }
 
     @Override protected String format() { return "(flt)%1"; }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/ToIntegerNode.java b/src/main/java/com/seaofnodes/simple/node/ToIntegerNode.java
index 9136aacc..33806300 100644
--- a/src/main/java/com/seaofnodes/simple/node/ToIntegerNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ToIntegerNode.java
@@ -7,7 +7,7 @@ import com.seaofnodes.simple.type.TypeInteger;
 // Truncate toward zero, saturating overflow; NaN converts to zero.
 public class ToIntegerNode extends Node {
     public ToIntegerNode(Node lhs) { super(null,lhs); }
-
+    @Override public Tag serialTag() { return Tag.ToInteger; }
     @Override public String label() { return "ToInteger"; }
     @Override protected String format() { return "(int)%1"; }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/TypeNode.java b/src/main/java/com/seaofnodes/simple/node/TypeNode.java
index 970472da..3ab2d6f9 100644
--- a/src/main/java/com/seaofnodes/simple/node/TypeNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/TypeNode.java
@@ -2,6 +2,7 @@ package com.seaofnodes.simple.node;
 
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.BAOS;
 import com.seaofnodes.simple.util.Utils;
 import java.util.BitSet;
 import java.util.HashMap;
diff --git a/src/main/java/com/seaofnodes/simple/node/XCtrlNode.java b/src/main/java/com/seaofnodes/simple/node/XCtrlNode.java
index 3792e224..32e1deb9 100644
--- a/src/main/java/com/seaofnodes/simple/node/XCtrlNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/XCtrlNode.java
@@ -8,7 +8,7 @@ import com.seaofnodes.simple.type.Type;
 
 public class XCtrlNode extends CFGNode {
     public XCtrlNode() { super(new Node[]{CodeGen.CODE._start}); }
-
+    @Override public Tag serialTag() { return Tag.XCtrl; }
     @Override protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) { return p.p("Xctrl"); }
     @Override public boolean isConst() { return true; }
     @Override  public Type compute() { return Type.XCONTROL; }
diff --git a/src/main/java/com/seaofnodes/simple/node/XorNode.java b/src/main/java/com/seaofnodes/simple/node/XorNode.java
index e9cd13a5..c825f396 100644
--- a/src/main/java/com/seaofnodes/simple/node/XorNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/XorNode.java
@@ -6,7 +6,7 @@ import com.seaofnodes.simple.type.TypeInteger;
 
 public class XorNode extends ArithNode {
     public XorNode(Parser.Lexer loc, Node lhs, Node rhs) { super(loc, lhs, rhs, (byte)1); }
-
+    @Override public Tag serialTag() { return Tag.Xor; }
 
     @Override public String op() { return "^"; }
     @Override long doOp( long x, long y ) { return x ^ y; }