From 2aa8c5d1d0659bd1c828134f1a1f14d025a2d0f1 Mon Sep 17 00:00:00 2001
From: Cliff Click <cliffc@acm.org>
Date: Fri, 7 Feb 2025 08:58:36 -0800
Subject: Ch# Chapter 19: Instruction Selection and Portable Compilation
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: hadha <helsgithub15@gmail.com>
Co-authored-by: Tamás Hadházy <85063808+Hels15@users.noreply.github.com>
---
 .../java/com/seaofnodes/simple/ASMPrinter.java     | 140 +++++++
 src/main/java/com/seaofnodes/simple/Ary.java       |  34 +-
 src/main/java/com/seaofnodes/simple/CodeGen.java   | 241 ++++++++++--
 .../com/seaofnodes/simple/GlobalCodeMotion.java    |  67 ++--
 .../com/seaofnodes/simple/GraphVisualizer.java     |   2 +-
 src/main/java/com/seaofnodes/simple/IRPrinter.java |  27 +-
 src/main/java/com/seaofnodes/simple/IterPeeps.java |  48 +--
 src/main/java/com/seaofnodes/simple/JSViewer.java  |  30 +-
 .../java/com/seaofnodes/simple/ListScheduler.java  | 245 +++++++++---
 src/main/java/com/seaofnodes/simple/Machine.java   |  21 ++
 src/main/java/com/seaofnodes/simple/Parser.java    | 107 +++---
 src/main/java/com/seaofnodes/simple/RegMask.java   |  39 ++
 src/main/java/com/seaofnodes/simple/SB.java        |  17 +
 .../java/com/seaofnodes/simple/node/AddNode.java   |   5 +-
 .../java/com/seaofnodes/simple/node/BoolNode.java  |  27 +-
 .../java/com/seaofnodes/simple/node/CFGNode.java   |  18 +-
 .../java/com/seaofnodes/simple/node/CProjNode.java |   4 +-
 .../com/seaofnodes/simple/node/CallEndNode.java    |  12 +-
 .../java/com/seaofnodes/simple/node/CallNode.java  |  20 +-
 .../com/seaofnodes/simple/node/ConstantNode.java   |  14 +-
 .../java/com/seaofnodes/simple/node/CtrlNode.java  |   3 +-
 .../java/com/seaofnodes/simple/node/FunNode.java   |  38 +-
 .../java/com/seaofnodes/simple/node/IfNode.java    |   7 +-
 .../java/com/seaofnodes/simple/node/LoadNode.java  |  47 ++-
 .../java/com/seaofnodes/simple/node/LoopNode.java  |   1 +
 .../seaofnodes/simple/node/MachConcreteNode.java   |  27 ++
 .../java/com/seaofnodes/simple/node/MachNode.java  |  49 +++
 .../com/seaofnodes/simple/node/MemMergeNode.java   |   8 +-
 .../java/com/seaofnodes/simple/node/MemOpNode.java |  13 +
 .../java/com/seaofnodes/simple/node/MulNode.java   |  30 +-
 .../java/com/seaofnodes/simple/node/MultiUse.java  |   5 -
 .../java/com/seaofnodes/simple/node/NewNode.java   |  30 +-
 src/main/java/com/seaofnodes/simple/node/Node.java | 107 +++---
 .../java/com/seaofnodes/simple/node/ParmNode.java  |   3 +-
 .../java/com/seaofnodes/simple/node/PhiNode.java   |   7 +-
 .../java/com/seaofnodes/simple/node/ProjNode.java  |   6 +-
 .../com/seaofnodes/simple/node/ReadOnlyNode.java   |   1 +
 .../com/seaofnodes/simple/node/RegionNode.java     |  70 ++--
 .../com/seaofnodes/simple/node/ReturnNode.java     |   5 +-
 .../java/com/seaofnodes/simple/node/ScopeNode.java |   4 +-
 .../java/com/seaofnodes/simple/node/StartNode.java |   6 +-
 .../java/com/seaofnodes/simple/node/StopNode.java  |   1 +
 .../java/com/seaofnodes/simple/node/StoreNode.java |  46 +--
 .../java/com/seaofnodes/simple/node/XCtrlNode.java |   3 +-
 .../simple/node/cpus/x86_64_v2/AddFMemX86.java     |  33 ++
 .../simple/node/cpus/x86_64_v2/AddFX86.java        |  29 ++
 .../simple/node/cpus/x86_64_v2/AddIX86.java        |  39 ++
 .../simple/node/cpus/x86_64_v2/AddMemX86.java      |  25 ++
 .../simple/node/cpus/x86_64_v2/AddX86.java         |  29 ++
 .../simple/node/cpus/x86_64_v2/AndIX86.java        |  42 +++
 .../simple/node/cpus/x86_64_v2/CallRX86.java       |  31 ++
 .../simple/node/cpus/x86_64_v2/CallX86.java        |  40 ++
 .../simple/node/cpus/x86_64_v2/CmpIX86.java        |  43 +++
 .../simple/node/cpus/x86_64_v2/CmpMemX86.java      |  33 ++
 .../simple/node/cpus/x86_64_v2/CmpX86.java         |  27 ++
 .../simple/node/cpus/x86_64_v2/DivFX86.java        |  33 ++
 .../simple/node/cpus/x86_64_v2/DivX86.java         |  31 ++
 .../simple/node/cpus/x86_64_v2/FltX86.java         |  36 ++
 .../simple/node/cpus/x86_64_v2/FunX86.java         |  21 ++
 .../simple/node/cpus/x86_64_v2/I2f8X86.java        |  28 ++
 .../simple/node/cpus/x86_64_v2/IntX86.java         |  45 +++
 .../simple/node/cpus/x86_64_v2/JmpX86.java         |  46 +++
 .../simple/node/cpus/x86_64_v2/LeaX86.java         |  42 +++
 .../simple/node/cpus/x86_64_v2/LoadX86.java        |  25 ++
 .../simple/node/cpus/x86_64_v2/MemAddX86.java      |  28 ++
 .../simple/node/cpus/x86_64_v2/MemOpX86.java       |  87 +++++
 .../simple/node/cpus/x86_64_v2/MulFX86.java        |  30 ++
 .../simple/node/cpus/x86_64_v2/MulIX86.java        |  36 ++
 .../simple/node/cpus/x86_64_v2/MulX86.java         |  30 ++
 .../simple/node/cpus/x86_64_v2/NewX86.java         |  40 ++
 .../simple/node/cpus/x86_64_v2/OrIX86.java         |  44 +++
 .../simple/node/cpus/x86_64_v2/ParmX86.java        |  24 ++
 .../simple/node/cpus/x86_64_v2/ProjX86.java        |  23 ++
 .../simple/node/cpus/x86_64_v2/RetX86.java         |  48 +++
 .../simple/node/cpus/x86_64_v2/SarX86.java         |  40 ++
 .../simple/node/cpus/x86_64_v2/SetX86.java         |  39 ++
 .../simple/node/cpus/x86_64_v2/ShlIX86.java        |  38 ++
 .../simple/node/cpus/x86_64_v2/ShrIX86.java        |  39 ++
 .../simple/node/cpus/x86_64_v2/StoreX86.java       |  30 ++
 .../simple/node/cpus/x86_64_v2/SubFX86.java        |  29 ++
 .../simple/node/cpus/x86_64_v2/SubX86.java         |  29 ++
 .../simple/node/cpus/x86_64_v2/TFPX86.java         |  41 ++
 .../simple/node/cpus/x86_64_v2/XorIX86.java        |  42 +++
 .../simple/node/cpus/x86_64_v2/x86_64_v2.java      | 418 +++++++++++++++++++++
 src/main/java/com/seaofnodes/simple/type/Type.java |   4 -
 .../com/seaofnodes/simple/type/TypeFunPtr.java     |  68 +---
 .../com/seaofnodes/simple/type/TypeStruct.java     |  10 +-
 87 files changed, 2995 insertions(+), 535 deletions(-)
 create mode 100644 src/main/java/com/seaofnodes/simple/ASMPrinter.java
 create mode 100644 src/main/java/com/seaofnodes/simple/Machine.java
 create mode 100644 src/main/java/com/seaofnodes/simple/RegMask.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/MachConcreteNode.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/MachNode.java
 delete mode 100644 src/main/java/com/seaofnodes/simple/node/MultiUse.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFMemX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddIX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddMemX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AndIX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallRX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpIX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpMemX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivFX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FltX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FunX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/I2f8X86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/IntX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/LeaX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/LoadX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemAddX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulFX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulIX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NewX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/OrIX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ParmX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ProjX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/RetX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SarX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ShlIX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ShrIX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/StoreX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubFX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/TFPX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/XorIX86.java
 create mode 100644 src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java

(limited to 'src/main')

diff --git a/src/main/java/com/seaofnodes/simple/ASMPrinter.java b/src/main/java/com/seaofnodes/simple/ASMPrinter.java
new file mode 100644
index 00000000..5cc13210
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/ASMPrinter.java
@@ -0,0 +1,140 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.type.TypeFunPtr;
+import com.seaofnodes.simple.type.TypeMem;
+import com.seaofnodes.simple.type.TypeRPC;
+
+public abstract class ASMPrinter {
+
+    public static SB print(SB sb, CodeGen code) {
+        if( code._cfg==null )
+            return sb.p("Need _cfg set, run after GCM");
+
+        // instruction address
+        int iadr = 0;
+        for( int i=0; i<code._cfg._len; i++ )
+            if( code._cfg.at(i) instanceof FunNode fun )
+                iadr = print(iadr,sb,code,fun,i);
+        return sb;
+    }
+
+    private static int print(int iadr, SB sb, CodeGen code, FunNode fun, int cfgidx) {
+        // Function header
+        sb.nl().p("---");
+        fun.sig().print(sb);
+        sb.p("---------------------------").nl();
+
+
+        while( !(code._cfg.at(cfgidx) instanceof ReturnNode) )
+            iadr = doBlock(iadr,sb,code,fun,cfgidx++);
+
+        // Function separator
+        sb.p("---");
+        fun.sig().print(sb);
+        sb.p("---------------------------").nl();
+        return iadr;
+    }
+
+    static int doBlock(int iadr, SB sb, CodeGen code, FunNode fun, int cfgidx) {
+        CFGNode bb = code._cfg.at(cfgidx);
+        if( bb != fun && !(bb instanceof IfNode) && !(bb instanceof CallEndNode) && !(bb instanceof CallNode)  && !(bb instanceof CProjNode && bb.in(0) instanceof CallEndNode ))
+            sb.p("L").p(bb._nid).p(":").nl();
+
+        if( !(bb instanceof CallNode) )
+            for( Node n : bb._outputs )
+                iadr = doInst(iadr, sb,code,fun,bb,n);
+
+        return iadr;
+    }
+
+    static int doInst(int iadr, SB sb, CodeGen code, FunNode fun, CFGNode bb, Node n) {
+        final int encWidth = 8;
+        final int opWidth = 5;
+        final int argWidth = 30;
+
+        if( n instanceof  CProjNode ) return iadr;
+
+        // Phis are useful before (and during) reg alloc
+        if( n instanceof PhiNode phi ) {
+            if( phi._type instanceof TypeMem || phi._type instanceof TypeRPC ) return iadr; // Nothing for the hidden ones
+            sb.fix(4," ").p(" ").fix(encWidth,"").p("  ").fix(opWidth,phi._label).p(" ");
+            sb.p(code.reg(n));
+            if( !(n instanceof ParmNode) ) {
+                sb.p(" = phi( ");
+                for( int i=1; i<n.nIns(); i++ )
+                    sb.p("N").p(n.in(i)._nid).p(",");
+                sb.unchar().p(" )");
+            }
+            sb.nl();
+            return iadr;
+        }
+
+        // All blocks ending in a Region will need to either fall into or jump
+        // to this block.  Until the post-reg-alloc block layout cleanup, we
+        // need to assume a jump.  There's no real hardware op here, yet.
+        if( n instanceof RegionNode && !(n instanceof FunNode) ) {
+            sb.hex4(iadr++).p(" ").fix(encWidth,"??").p("  ").fix(opWidth,"JMP").p(" ").fix(argWidth,"L"+n._nid).nl();
+            return iadr;
+        }
+
+        // ProjNodes following a multi (e.g. Call or New results),
+        // get indent slightly and just print their index & node#
+        if( n instanceof ProjNode proj ) {
+            if( proj._type instanceof TypeMem ) return iadr; // Nothing for the hidden ones
+            sb.fix(4," ").p(" ").fix(encWidth,"").p("    ").fix(opWidth,proj._label==null ? "---" : proj._label).p(" ").p(code.reg(n)).nl();
+            return iadr;
+        }
+
+        // ADDR ENCODING  Op--- dst = src op src       // Comment
+        // 1234 abcdefgh  ld4   RAX = [Rbase + off]    // Comment
+        sb.hex4(iadr);
+        sb.p(" ");
+
+        // Encoding
+        int size = 1;           // TODO: Fake encoding size
+        iadr += size;
+        sb.fix(encWidth,"??");
+        sb.p("  ");
+
+        // Op; generally "ld4" or "call"
+        sb.fix(opWidth, n instanceof MachNode mach ? mach.op() : n.label());
+        sb.p(" ");
+
+        // General asm args
+        if( n instanceof MachNode mach ) {
+            int old = sb.len();
+            mach.asm(code,sb);
+            sb.fix(argWidth-(sb.len()-old),""); // Pad out
+
+        } else if( !(n._type instanceof TypeMem) ) {
+            // Room for some inputs
+            sb.fix(5, n._nid+":" );
+            int off = 0;
+            for( int i=0; i<n.nIns(); i++ ) {
+                sb.fix(5, n.in(i) == null ? "___" : String.valueOf(n.in(i)._nid));
+                off += 5;
+                if( off >= argWidth ) break;
+            }
+            if( off < argWidth ) sb.fix(argWidth-off,"");
+        }
+        sb.p(" ");
+
+        // Comment
+        String comment = n.comment();
+        if( comment!=null ) sb.p("// ").p(comment);
+
+        sb.nl();
+
+        // MultiNodes are immediately followed by projection(s)
+        if( !(n instanceof CFGNode) && n instanceof MultiNode ) {
+            for( Node proj : n._outputs ) {
+                assert proj instanceof ProjNode;
+                doInst(iadr,sb,code,fun,bb,proj);
+            }
+        }
+
+        return iadr;
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/Ary.java b/src/main/java/com/seaofnodes/simple/Ary.java
index b5184948..73ada8e0 100644
--- a/src/main/java/com/seaofnodes/simple/Ary.java
+++ b/src/main/java/com/seaofnodes/simple/Ary.java
@@ -42,8 +42,7 @@ public class Ary<E> extends AbstractList<E> implements List<E> {
     }
     /** @return remove and return last element */
     public E pop( ) {
-        range_check(0);
-        return _es[--_len];
+        return _len==0 ? null : _es[--_len];
     }
     @Override public E removeLast() { return pop(); }
 
@@ -93,6 +92,22 @@ public class Ary<E> extends AbstractList<E> implements List<E> {
         return old;
     }
 
+    /** Set existing element
+     *  @param i element to set
+     *  @param e value to set
+     *  @return old value
+     *  @exception AIOOBE if !(0 <= i < _len)
+     */
+    public E setX( int i, E e ) {
+        if( i >= _len ) {
+            while( i >= _es.length ) _es = Arrays.copyOf( _es, _es.length << 1 );
+            _len = i+1;
+        }
+        E old = _es[i];
+        _es[i] = e;
+        return old;
+    }
+
     public Ary<E> setLen( int len ) {
         if( len > _len )
             while( len>= _es.length ) _es = Arrays.copyOf(_es,_es.length<<1);
@@ -103,13 +118,14 @@ public class Ary<E> extends AbstractList<E> implements List<E> {
         return this;
     }
 
-    public void swap( int i, int j ) {
+    public E swap( int i, int j ) {
         range_check(i);
         range_check(j);
-        if( i==j ) return;
         E tmp = _es[i];
+        if( i==j ) return tmp;
         _es[i] = _es[j];
         _es[j] = tmp;
+        return tmp;
     }
 
 
@@ -139,12 +155,12 @@ public class Ary<E> extends AbstractList<E> implements List<E> {
         return this;
     }
 
-  /** @return compact array version */
-  public E[] asAry() { return Arrays.copyOf(_es,_len); }
+    /** @return compact array version */
+    public E[] asAry() { return Arrays.copyOf(_es,_len); }
 
-  /** Sorts in-place
-   *  @param c Comparator to sort by */
-  public void sort_update(Comparator<? super E> c ) { Arrays.sort(_es, 0, _len, c);  }
+    /** Sorts in-place
+     *  @param c Comparator to sort by */
+    public void sort_update(Comparator<? super E> c ) { Arrays.sort(_es, 0, _len, c);  }
 
     /** Find the first matching element using ==, or -1 if none.  Note that
      *  most del calls shuffle the list, so the first element might be random.
diff --git a/src/main/java/com/seaofnodes/simple/CodeGen.java b/src/main/java/com/seaofnodes/simple/CodeGen.java
index 47616b51..c48a4162 100644
--- a/src/main/java/com/seaofnodes/simple/CodeGen.java
+++ b/src/main/java/com/seaofnodes/simple/CodeGen.java
@@ -1,72 +1,160 @@
  package com.seaofnodes.simple;
 
 import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.node.cpus.x86_64_v2.MemOpX86;
 import com.seaofnodes.simple.type.*;
+import java.util.BitSet;
 import java.util.HashMap;
+import java.util.IdentityHashMap;
 
 public class CodeGen {
+    // Last created CodeGen as a global; used all over to avoid passing about a
+    // "context".
+    public static CodeGen CODE;
 
     public enum Phase {
-        Parse, Opto, TypeCheck, Schedule, LocalSched, RegAlloc;
+        Parse,                  // Parse ASCII text into Sea-of-Nodes IR
+        Opto,                   // Run ideal optimizations
+        TypeCheck,              // Last check for bad programs
+        InstructionSelection,   // Convert to target hardware nodes
+        Schedule,               // Global schedule (code motion) nodes
+        LocalSched,             // Local schedule
+        RegAlloc;               // Register allocation
+    }
+    public enum CallingConv {
+        Win64,
+        SystemV
     }
     public Phase _phase;
 
+    // ---------------------------
+    // Compilation source code
     public final String _src;
     // Compile-time known initial argument type
     public final TypeInteger _arg;
+    public CallingConv _callingConv;
+
+    // ---------------------------
+    public CodeGen( String src ) { this(src, TypeInteger.BOT, 123L ); }
+    public CodeGen( String src, TypeInteger arg, long workListSeed ) {
+        CODE = this;
+        _phase = null;
+        _callingConv = null;
+        _start = new StartNode(arg);
+        _stop = new StopNode(src);
+        _src = src;
+        _arg = arg;
+        _iter = new IterPeeps(workListSeed);
+        P = new Parser(this,arg);
+    }
+
+
+    // ---------------------------
+    /**
+     *  A counter, for unique node id generation.  Starting with value 1, to
+     *  avoid bugs confusing node ID 0 with uninitialized values.
+     */
+    private int _uid = 1;
+    public int UID() { return _uid; }
+    public int getUID() { return _uid++; }
+
+    // Next available memory alias number
+    private int _alias = 2; // 0 is for control, 1 for memory
+    public  int getALIAS() { return _alias++; }
+
 
-    public Parser P;
+    // Popular visit bitset, declared here, so it gets reused all over
+    public final BitSet _visit = new BitSet();
+    public BitSet visit() { assert _visit.isEmpty(); return _visit; }
+
+    // Start and stop; end points of the generated IR
     public StartNode _start;
-    public  StopNode _stop ;
+    public StopNode  _stop;
 
+    // Global Value Numbering.  Hash over opcode and inputs; hits in this table
+    // are structurally equal.
+    public final HashMap<Node,Node> _gvn = new HashMap<>();
+
+    // Compute "function indices": FIDX.
+    // Each new request at the same signature gets a new FIDX.
+    private final HashMap<TypeTuple,Integer> FIDXS = new HashMap<>();
+    public TypeFunPtr makeFun( TypeTuple sig, Type ret ) {
+        Integer i = FIDXS.get(sig);
+        int fidx = i==null ? 0 : i;
+        FIDXS.put(sig,fidx+1);  // Track count per sig
+        assert fidx<64;         // TODO: need a larger FIDX space
+        return TypeFunPtr.make((byte)2,sig,ret, 1L<<fidx );
+    }
+    // Signature for MAIN
+    public TypeFunPtr _main = makeFun(TypeTuple.MAIN,Type.BOTTOM);
+    // Reverse from a constant function pointer to the IR function being called
+    public FunNode link( TypeFunPtr tfp ) {
+        assert tfp.isConstant();
+        return _linker.get(tfp.makeFrom(Type.BOTTOM));
+    }
+
+    // Insert linker mapping from constant function signature to the function
+    // being called.
+    public void link(FunNode fun) {
+        _linker.put(fun.sig().makeFrom(Type.BOTTOM),fun);
+    }
 
     // "Linker" mapping from constant TypeFunPtrs to heads of function.  These
     // TFPs all have exact single fidxs and their return is wiped to BOTTOM (so
     // the return is not part of the match).
     private final HashMap<TypeFunPtr,FunNode> _linker = new HashMap<>();
 
+    // Parser object
+    public final Parser P;
 
-    // Last created CodeGen as a global, for easier debugging prints
-    public static CodeGen CODE;
-
-    CodeGen( String src, TypeInteger arg ) { _phase = null; _src = src; _arg=arg; CODE=this; }
-    public CodeGen( String src ) { this(src,TypeInteger.BOT); }
-
-    public CodeGen parse() { return parse(false); }
-    public CodeGen parse(boolean disable) {
+    // Parse ASCII text into Sea-of-Nodes IR
+    public CodeGen parse() {
         assert _phase == null;
         _phase = Phase.Parse;
-        _linker.clear();
 
-        P = new Parser(_src,_arg);
-        Node._disablePeephole = disable;
-        _stop = P.parse();
-        _start = Parser.START;   // Capture global start
+        P.parse();
         JSViewer.show();
-        P = null;                // No longer parsing
         return this;
     }
 
+
+    // ---------------------------
+    // Iterator peepholes.
+    public final IterPeeps _iter;
+    // Stop tracking deps while assertin
+    public boolean _midAssert;
+    // Statistics on peepholes
+    public int _iter_cnt, _iter_nop_cnt;
+    // Stat gathering
+    public void iterCnt() { if( !_midAssert ) _iter_cnt++; }
+    public void iterNop() { if( !_midAssert ) _iter_nop_cnt++; }
+
+    // Run ideal optimizations
     public CodeGen opto() {
         assert _phase == Phase.Parse;
         _phase = Phase.Opto;
 
-        // Optimization
-        IterPeeps.iterate(_stop);
+        // Pessimistic peephole optimization on a worklist
+        _iter.iterate(this);
 
         // TODO:
         // Optimistic
+        // TODO:
+        // loop unroll, peel, RCE, etc
         return this;
     }
+    public <N extends Node> N add( N n ) { return (N)_iter.add(n); }
+    public void addAll( Ary<Node> ary ) { _iter.addAll(ary); }
+
 
+    // ---------------------------
+    // Last check for bad programs
     public CodeGen typeCheck() {
         // Demand phase Opto for cleaning up dead control flow at least,
-        // required for the following GCM.  Note that peeps can be disabled,
-        // but still the dead CFG will get cleaned.
-        assert _phase == Phase.Opto;
+        // required for the following GCM.
+        assert _phase.ordinal() <= Phase.Opto.ordinal();
         _phase = Phase.TypeCheck;
 
-        // Type check
         Parser.ParseException err = _stop.walk( Node::err );
         if( err != null )
             throw err;
@@ -74,22 +162,98 @@ public class CodeGen {
     }
 
 
+    // ---------------------------
+    // Code generation CPU target
+    public Machine _mach;
+
+    // Convert to target hardware nodes
+    public CodeGen instSelect( String cpu, String callingConv ) {
+        assert _phase.ordinal() <= Phase.TypeCheck.ordinal();
+        _phase = Phase.InstructionSelection;
+
+        _callingConv = switch(callingConv) {
+        case "SystemV" -> CallingConv.SystemV;
+        case "Win64"   -> CallingConv.Win64;
+        default -> throw Utils.TODO(); // Unknown calling convention
+        };
+
+        // Look for CPU in fixed named place:
+        //   com.seaofnodes.simple.node.cpus."cpu"."cpu.class"
+        String clzFile = "com.seaofnodes.simple.node.cpus."+cpu+"."+cpu;
+        try { _mach = ((Class<Machine>) Class.forName( clzFile )).getDeclaredConstructor().newInstance(); }
+        catch( Exception e ) { throw new RuntimeException(e); }
+
+        // Convert to machine ops
+        _uid = 1;               // All new machine nodes reset numbering
+        var map = new IdentityHashMap<Node,Node>();
+        _instSelect( _stop, map );
+        _stop  = ( StopNode)map.get(_stop );
+        _start = (StartNode)map.get(_start);
+        _instOuts(_stop,visit());
+        _visit.clear();
+        return this;
+    }
+
+    // Walk all ideal nodes, recursively mapping ideal to machine nodes, then
+    // make a machine node for "this".
+    private Node _instSelect( Node n, IdentityHashMap<Node,Node> map ) {
+        if( n==null ) return null;
+        Node x = map.get(n);
+        if( x !=null ) return x; // Been there, done that
+
+        // If n is a MachConcrete, then its part of a multi-node expansion.
+        // It does not need instruction selection (already selected!)
+        // but it does need its inputs walked.
+        if( n instanceof MachConcreteNode || n instanceof MemOpX86 ) {
+            for( int i=0; i < n.nIns(); i++ )
+                n._inputs.set(i, _instSelect(n.in(i),map) );
+            return n;
+        }
+
+        // Produce a machine node from n; map it to flag as done so stops cycles.
+        map.put(n, x=_mach.instSelect(n) );
+        // Walk machine op and replace inputs with mapped inputs
+        for( int i=0; i < x.nIns(); i++ )
+            x._inputs.set(i, _instSelect(x.in(i),map) );
+        if( x instanceof MachNode mach )
+            mach.postSelect();  // Post selection action
+
+        // Updates forward edges only.
+        n._outputs.clear();
+        return x;
+    }
+
+    // Walk all machine Nodes, and set their output edges
+    private void _instOuts( Node n, BitSet visit ) {
+        if( visit.get(n._nid) ) return;
+        visit.set(n._nid);
+        for( Node in : n._inputs )
+            if( in!=null ) {
+                in._outputs.push(n);
+                _instOuts(in,visit);
+            }
+    }
+
+
+    // ---------------------------
+    // Control Flow Graph in RPO order.
+    Ary<CFGNode> _cfg = new Ary<>(CFGNode.class);
+
+    // Global schedule (code motion) nodes
     public CodeGen GCM() { return GCM(false); }
     public CodeGen GCM( boolean show) {
-        assert _phase == Phase.TypeCheck;
+        assert _phase.ordinal() <= Phase.InstructionSelection.ordinal();
         _phase = Phase.Schedule;
 
         // Build the loop tree, fix never-exit loops
         _start.buildLoopTree(_stop);
+        GlobalCodeMotion.buildCFG(this);
         if( show )
             System.out.println(new GraphVisualizer().generateDotOutput(_stop,null,null));
-
-        // TODO:
-        // loop unroll, peel, RCE, etc
-        GlobalCodeMotion.buildCFG(_start,_stop);
         return this;
     }
 
+    // ---------------------------
     // Local (basic block) scheduler phase, a classic list scheduler
     public CodeGen localSched() {
         assert _phase == Phase.Schedule;
@@ -98,25 +262,26 @@ public class CodeGen {
         return this;
      }
 
-    // Reverse from a constant function pointer to the IR function being called
-    public FunNode link( TypeFunPtr tfp ) {
-        assert tfp.isConstant();
-        return _linker.get(tfp.makeFrom(Type.BOTTOM));
-    }
 
-    public void link(FunNode fun) {
-        _linker.put(fun.sig().makeFrom(Type.BOTTOM),fun);
+    // ---------------------------
+    public String reg(Node n) {
+        if( _phase == Phase.RegAlloc ) throw Utils.TODO();
+        return "N"+ n._nid;
     }
 
+
+    // ---------------------------
+    SB asm(SB sb) { return ASMPrinter.print(sb,this); }
+    String asm() { return asm(new SB()).toString(); }
+
+
     // Testing shortcuts
     Node ctrl() { return _stop.ret().ctrl(); }
     Node expr() { return _stop.ret().expr(); }
     String print() { return _stop.print(); }
 
     // Debugging helper
-    @Override public String toString() {
-        return _stop.p(9999);
-    }
+    @Override public String toString() { return _stop.p(9999); }
 
     // Debugging helper
     public Node f(int idx) { return _stop.find(idx); }
diff --git a/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java b/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java
index d3ee62c3..12dd9243 100644
--- a/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java
+++ b/src/main/java/com/seaofnodes/simple/GlobalCodeMotion.java
@@ -10,46 +10,54 @@ public abstract class GlobalCodeMotion {
     // Arrange that the existing isCFG() Nodes form a valid CFG.  The
     // Node.use(0) is always a block tail (either IfNode or head of the
     // following block).  There are no unreachable infinite loops.
-    public static void buildCFG( StartNode start, StopNode stop ) {
-        schedEarly(start);
-        schedLate(stop);
+    public static void buildCFG( CodeGen code ) {
+        Ary<CFGNode> rpo = new Ary<>(CFGNode.class);
+        _rpo_cfg(null, code._start, code.visit(), rpo);
+        // Reverse in-place
+        for( int i=0; i< rpo.size()>>1; i++ ) {
+            int j = rpo.size()-1-i;
+            CFGNode tmp = rpo.get(i);
+            rpo.set(i, rpo.get(j));
+            rpo.set(j, tmp);
+        }
+        // Set global CFG
+        code._cfg = rpo;
+
+        schedEarly(code);
+        code._visit.clear();
+        schedLate (code);
     }
 
+    // Post-Order of CFG
+    private static void _rpo_cfg(CFGNode def, Node use, BitSet visit, Ary<CFGNode> rpo) {
+        if( !(use instanceof CFGNode cfg) || visit.get(cfg._nid) )
+            return;             // Been there, done that
+        if( def instanceof CallNode && cfg instanceof FunNode )
+            return;           // Ignore linked function calls
+        visit.set(cfg._nid);
+        for( Node useuse : cfg._outputs )
+            _rpo_cfg(cfg,useuse,visit,rpo);
+        rpo.add(cfg);
+    }
 
     // ------------------------------------------------------------------------
     // Visit all nodes in CFG Reverse Post-Order, essentially defs before uses
     // (except at loops).  Since defs are visited first - and hoisted as early
     // as possible, when we come to a use we place it just after its deepest
     // input.
-    private static void schedEarly(StartNode start) {
-        ArrayList<CFGNode> rpo = new ArrayList<>();
-        BitSet visit = new BitSet();
-        _rpo_cfg(null, start, visit, rpo);
+    private static void schedEarly(CodeGen code) {
         // Reverse Post-Order on CFG
-        for( int j=rpo.size()-1; j>=0; j-- ) {
-            CFGNode cfg = rpo.get(j);
+        for( CFGNode cfg : code._cfg ) {
             cfg.loopDepth();
             for( Node n : cfg._inputs )
-                _schedEarly(n,visit);
+                _schedEarly(n,code._visit );
             if( cfg instanceof RegionNode )
                 for( Node phi : cfg._outputs )
                     if( phi instanceof PhiNode )
-                        _schedEarly(phi,visit);
+                        _schedEarly(phi,code._visit );
         }
     }
 
-    // Post-Order of CFG
-    private static void _rpo_cfg(CFGNode def, Node use, BitSet visit, ArrayList<CFGNode> rpo) {
-        if( !(use instanceof CFGNode cfg) || visit.get(cfg._nid) )
-            return;             // Been there, done that
-        if( def instanceof CallNode && cfg instanceof FunNode )
-            return;           // Ignore linked function calls
-        visit.set(cfg._nid);
-        for( Node useuse : cfg._outputs )
-            _rpo_cfg(cfg,useuse,visit,rpo);
-        rpo.add(cfg);
-    }
-
     private static void _schedEarly(Node n, BitSet visit) {
         if( n==null || visit.get(n._nid) ) return; // Been there, done that
         assert !(n instanceof CFGNode);
@@ -61,24 +69,25 @@ public abstract class GlobalCodeMotion {
         for( Node def : n._inputs )
             if( def!=null && !(def instanceof PhiNode) )
                 _schedEarly(def,visit);
+
         // If not-pinned (e.g. constants, projections, phi) and not-CFG
         if( !n.isPinned() ) {
             // Schedule at deepest input
-            CFGNode early = Parser.START; // Maximally early, lowest idepth
+            CFGNode early = CodeGen.CODE._start; // Maximally early, lowest idepth
             if( n.in(0) instanceof CFGNode cfg ) early = cfg;
             for( int i=1; i<n.nIns(); i++ )
                 if( n.in(i)!=null && n.in(i).cfg0().idepth() > early.idepth() )
                     early = n.in(i).cfg0(); // Latest/deepest input
-            n.setDef(0,early);              // First place this can go
+            n.setDef(0,early);
         }
     }
 
     // ------------------------------------------------------------------------
-    private static void schedLate( StopNode stop) {
-        CFGNode[] late = new CFGNode[Node.UID()];
-        Node[] ns = new Node[Node.UID()];
+    private static void schedLate( CodeGen code ) {
+        CFGNode[] late = new CFGNode[code.UID()];
+        Node[] ns = new Node[code.UID()];
         // Breadth-first scheduling
-        breadth(stop,ns,late);
+        breadth(code._stop,ns,late);
 
         // Copy the best placement choice into the control slot
         for( int i=0; i<late.length; i++ )
diff --git a/src/main/java/com/seaofnodes/simple/GraphVisualizer.java b/src/main/java/com/seaofnodes/simple/GraphVisualizer.java
index 5d6d3328..30e25916 100644
--- a/src/main/java/com/seaofnodes/simple/GraphVisualizer.java
+++ b/src/main/java/com/seaofnodes/simple/GraphVisualizer.java
@@ -22,7 +22,7 @@ public class GraphVisualizer {
     public GraphVisualizer(boolean separateControlCluster) { this._separateControlCluster = separateControlCluster; }
     public GraphVisualizer() { this(false); }
 
-    public String generateDotOutput(Parser parse) { return generateDotOutput(parse.STOP,parse._scope,parse._xScopes); }
+    public String generateDotOutput(Parser parse) { return generateDotOutput(parse._code._stop,parse._scope,parse._xScopes); }
     public String generateDotOutput(StopNode stop, Node scope, Stack<ScopeNode> xScopes) {
 
         // Since the graph has cycles, we need to create a flat list of all the
diff --git a/src/main/java/com/seaofnodes/simple/IRPrinter.java b/src/main/java/com/seaofnodes/simple/IRPrinter.java
index aa498b16..3cddacfd 100644
--- a/src/main/java/com/seaofnodes/simple/IRPrinter.java
+++ b/src/main/java/com/seaofnodes/simple/IRPrinter.java
@@ -6,7 +6,7 @@ import java.util.ArrayList;
 import java.util.BitSet;
 import java.util.HashMap;
 
-public class IRPrinter {
+public abstract class IRPrinter {
 
     // Print a node on 1 line, columnar aligned, as:
     // NNID NNAME DDEF DDEF  [[  UUSE UUSE  ]]  TYPE
@@ -55,10 +55,8 @@ public class IRPrinter {
             Node n = rpos.get(i);
             if( n instanceof CFGNode || n.isMultiHead() ) {
                 if( !gap ) sb.p("\n"); // Blank before multihead
-                if( n instanceof FunNode fun ) {
-                    TypeFunPtr sig = fun.sig();
-                    sig.print(sb.p("--- ").p(sig._name==null ? "" : sig._name).p(" "),false).p("----------------------\n");
-                }
+                if( n instanceof FunNode fun )
+                    fun.sig().print(sb.p("--- ").p(fun._name==null ? "" : fun._name).p(" "),false).p("----------------------\n");
                 printLine( n, sb );         // Print head
                 while( --i >= 0 ) {
                     Node t = rpos.get(i);
@@ -66,8 +64,8 @@ public class IRPrinter {
                     printLine( t, sb );
                 }
                 if( n instanceof ReturnNode ret ) {
-                    TypeFunPtr sig = ret.fun().sig();
-                    sig.print(sb.p("--- ").p(sig._name==null ? "" : sig._name).p(" "),false).p("----------------------\n");
+                    FunNode fun = ret.fun();
+                    fun.sig().print(sb.p("--- ").p(fun._name==null ? "" : fun._name).p(" "),false).p("----------------------\n");
                 }
                 if( !(n instanceof CallNode) ) {
                     sb.p("\n"); // Blank after multitail
@@ -176,12 +174,12 @@ public class IRPrinter {
     private static String _prettyPrintScheduled( Node node, int depth ) {
         // Backwards DFS walk to depth.
         HashMap<Integer,Integer> ds = new HashMap<>();
-        ArrayList<Node> ns = new ArrayList<>();
+        Ary<Node> ns = new Ary<>(Node.class);
         _walk(ds,ns,node,depth);
         // Remove data projections, these are force-printed behind their multinode head
         for( int i=0; i<ns.size(); i++ ) {
             if( ns.get(i) instanceof ProjNode proj && !(proj.in(0) instanceof CFGNode) ) {
-                Utils.del(ns,i--);
+                ns.del(i--);
                 ds.remove(proj._nid);
             }
         }
@@ -192,11 +190,11 @@ public class IRPrinter {
             CFGNode blk = null;
             for( Node n : ns ) {
                 CFGNode cfg = n instanceof CFGNode cfg0 && cfg0.blockHead() ? cfg0 : n.cfg0();
-                if( blk==null || cfg.idepth() < blk.idepth() || (blk instanceof FunNode && !(cfg instanceof FunNode)))
+                if( blk==null || cfg.idepth() < blk.idepth() )
                     blk = cfg;
             }
             Integer d = ds.remove(blk._nid);
-            ns.remove(blk);
+            ns.del(ns.find(blk));
 
             // Print block header
             sb.p("%-13.13s".formatted(label(blk)+":"));
@@ -244,7 +242,7 @@ public class IRPrinter {
         return sb.toString();
     }
 
-    private static void _walk( HashMap<Integer,Integer> ds, ArrayList<Node> ns, Node node, int d ) {
+    private static void _walk( HashMap<Integer,Integer> ds, Ary<Node> ns, Node node, int d ) {
         Integer nd = ds.get(node._nid);
         if( nd!=null && d <= nd ) return; // Been there, done that
         Integer old = ds.put(node._nid,d) ;
@@ -270,11 +268,12 @@ public class IRPrinter {
         if( !blk.blockHead() ) blk = blk.cfg(0);
         sb.p( "%-9.9s ".formatted( label( blk ) ) );
     }
-    static void printLine( Node n, SB sb, Ary<Node> bns, int i, HashMap<Integer,Integer> ds, ArrayList<Node> ns ) {
+    static void printLine( Node n, SB sb, Ary<Node> bns, int i, HashMap<Integer,Integer> ds, Ary<Node> ns ) {
         printLine( n, sb );
         if( i != -1 ) bns.del(i);
         ds.remove(n._nid);
-        ns.remove(n);
+        int idx = ns.find(n);
+        if( idx!=-1 ) ns.del(idx);
     }
 
 }
diff --git a/src/main/java/com/seaofnodes/simple/IterPeeps.java b/src/main/java/com/seaofnodes/simple/IterPeeps.java
index 998bd4f0..265e0b21 100644
--- a/src/main/java/com/seaofnodes/simple/IterPeeps.java
+++ b/src/main/java/com/seaofnodes/simple/IterPeeps.java
@@ -42,27 +42,25 @@ import java.util.Random;
  *   progressOnList(stop);`</li>
  * </ul>
  */
-public abstract class IterPeeps {
+public class IterPeeps {
 
-    private static final WorkList<Node> WORK = new WorkList<>();
+    private final WorkList<Node> _work;
 
-    public static <N extends Node> N add( N n ) {
-        return (N)WORK.push(n);
-    }
+    IterPeeps( long seed ) { _work = new WorkList<>(seed); }
 
-    public static void addAll( Ary<Node> ary ) {
-        WORK.addAll(ary);
-    }
+    public <N extends Node> N add( N n ) { return (N)_work.push(n); }
+
+    public void addAll( Ary<Node> ary ) { _work.addAll(ary); }
 
     /**
      * Iterate peepholes to a fixed point
      */
-    public static void iterate( StopNode stop) {
-        assert progressOnList(stop);
+    public void iterate( CodeGen code ) {
+        assert progressOnList(code);
         int cnt=0;
 
         Node n;
-        while( (n=WORK.pop()) != null ) {
+        while( (n=_work.pop()) != null ) {
             if( n.isDead() )  continue;
             cnt++;              // Useful for debugging, searching which peephole broke things
             Node x = n.peepholeOpt();
@@ -73,21 +71,21 @@ public abstract class IterPeeps {
                 // Changes require neighbors onto the worklist
                 if( x != n || !(x instanceof ConstantNode) ) {
                     // All outputs of n (changing node) not x (prior existing node).
-                    for( Node z : n._outputs ) WORK.push(z);
+                    for( Node z : n._outputs ) _work.push(z);
                     // Everybody gets a free "go again" in case they didn't get
                     // made in their final form.
-                    WORK.push(x);
+                    _work.push(x);
                     // If the result is not self, revisit all inputs (because
                     // there's a new user), and replace in the graph.
                     if( x != n ) {
-                        for( Node z : n. _inputs ) WORK.push(z);
+                        for( Node z : n. _inputs ) _work.push(z);
                         n.subsume(x);
                     }
                 }
                 // If there are distant neighbors, move to worklist
                 n.moveDepsToWorklist();
                 JSViewer.show(); // Show again
-                assert progressOnList(stop); // Very expensive assert
+                assert progressOnList(code); // Very expensive assert
             }
             if( n.isUnused() && !(n instanceof StopNode) )
                 n.kill();       // Just plain dead
@@ -96,7 +94,7 @@ public abstract class IterPeeps {
     }
 
     // Visit ALL nodes and confirm the invariant:
-    //   Either you are on the WORK worklist OR running `iter()` makes no progress.
+    //   Either you are on the _work worklist OR running `iter()` makes no progress.
 
     // This invariant ensures that no progress is missed, i.e., when the
     // worklist is empty we have indeed done all that can be done.  To help
@@ -107,30 +105,22 @@ public abstract class IterPeeps {
     // neighbors and these should fail, but will then try to add dependencies
     // {@link #Node.addDep} which is a side effect in an assert.  The {@link
     // #midAssert} is used to stop this side effect.
-    private static boolean MID_ASSERT;
-    public static boolean midAssert() { return MID_ASSERT; }
-    private static boolean progressOnList(Node stop) {
-        MID_ASSERT = true;
-        int old_cnt = Node.ITER_CNT, old_nop = Node.ITER_NOP_CNT;
-        Node changed = stop.walk( n -> {
+    private boolean progressOnList(CodeGen code) {
+        code._midAssert = true;
+        Node changed = code._stop.walk( n -> {
                 Node m = n;
                 if( n.compute().isa(n._type) && (!n.iskeep() || n._nid<=6) ) { // Types must be forwards, even if on worklist
-                    if( WORK.on(n) ) return null;
+                    if( _work.on(n) ) return null;
                     m = n.peepholeOpt();
                     if( m==null ) return null;
                 }
                 System.err.println("BREAK HERE FOR BUG");
                 return m;
             });
-        Node.ITER_CNT = old_cnt;  Node.ITER_NOP_CNT = old_nop;
-        MID_ASSERT = false;
+        code._midAssert = false;
         return changed==null;
     }
 
-    public static void reset() {
-        WORK.clear();
-    }
-
     /**
      * Classic WorkList, with a fast add/remove, dup removal, random pull.
      * The Node's nid is used to check membership in the worklist.
diff --git a/src/main/java/com/seaofnodes/simple/JSViewer.java b/src/main/java/com/seaofnodes/simple/JSViewer.java
index 7422767a..fcb0c28a 100644
--- a/src/main/java/com/seaofnodes/simple/JSViewer.java
+++ b/src/main/java/com/seaofnodes/simple/JSViewer.java
@@ -6,6 +6,7 @@ import java.io.IOException;
 import java.util.Stack;
 import java.nio.file.Paths;
 import java.util.Collection;
+import static com.seaofnodes.simple.CodeGen.CODE;
 
 public class JSViewer implements AutoCloseable {
     // Display programs in an endless loop
@@ -21,7 +22,6 @@ public class JSViewer implements AutoCloseable {
     static SimpleWebSocket SERVER;
 
     static int N;               // Dot frames
-    static CodeGen CODE;        //
 
     JSViewer() throws Exception {
         // Launch server; handshake
@@ -41,13 +41,13 @@ public class JSViewer implements AutoCloseable {
                 try {
                     N=0;
                     // Use parser scope, xscope when building views
-                    CODE = new CodeGen(src);
+                    CodeGen code = new CodeGen(src);
                     SHOW = true;
                     show();
                     // Parse program, generating views at every parse point
-                    CODE.parse();
+                    code.parse();
                     // No longer user parse internal state when building views
-                    CODE.opto();
+                    code.opto();
 
                     // Catch and ignore Parser errors
                 } catch(RuntimeException re) {
@@ -68,10 +68,10 @@ public class JSViewer implements AutoCloseable {
 
     public static void show() { if( SERVER!=null && SHOW ) _show(); }
     private static void _show() {
-        boolean midParse = CODE.P!=null;
         // Skip util we at least get the Parse object made
-        if( !midParse && (CODE._phase==null || CODE._phase == CodeGen.Phase.Parse) )
+        if( CODE._phase==null || CODE._phase.ordinal() < CodeGen.Phase.Parse.ordinal() )
             return;
+        boolean midParse = CODE._phase == CodeGen.Phase.Parse;
         Stack<ScopeNode> xScopes = midParse ? CODE.P._xScopes : null;
 
         Collection<Node> all = GraphVisualizer.findAll(xScopes, CODE._stop, midParse ? CODE.P._scope: null);
@@ -149,11 +149,13 @@ public class JSViewer implements AutoCloseable {
                 sb.i().p("<TR>");
                 n._outputs.sort((x,y) -> x instanceof ProjNode xp && y instanceof ProjNode yp ? (xp._idx - yp._idx) : ((x==null ? 99999 : x._nid) - (y==null ? 99999 : y._nid)));
                 boolean empty_row=true;
-                for( Node use : n._outputs )
-                    if( use instanceof MultiUse muse ) {
-                        cell(sb,use.glabel(),use,"p"+muse.idx());
+                for( Node use : n._outputs ) {
+                    int idx = idx(n);
+                    if( idx != -1 ) {
+                        cell(sb,use.glabel(),use,"p"+idx);
                         empty_row=false;
                     }
+                }
                 // At least one cell on row
                 if( empty_row )  sb.p("<TD></TD>");
                 sb.    p("</TR>").p("\n");
@@ -386,9 +388,15 @@ public class JSViewer implements AutoCloseable {
 
     }
 
+    // (C)Projection index or -1
+    private static int idx(Node n) {
+        return n instanceof ProjNode p ? p._idx : (n instanceof CProjNode cp ? cp._idx : -1);
+    }
+
     private static SB defPort(SB sb, Node def) {
-        return def instanceof MultiUse muse
-            ? sb.p(def.in(0).uniqueName()).p(":p").p(muse.idx())
+        int idx = idx(def);
+        return idx != -1
+            ? sb.p(def.in(0).uniqueName()).p(":p").p(idx)
             : sb.p(def.uniqueName());
     }
 }
diff --git a/src/main/java/com/seaofnodes/simple/ListScheduler.java b/src/main/java/com/seaofnodes/simple/ListScheduler.java
index 252a8f8e..18055e19 100644
--- a/src/main/java/com/seaofnodes/simple/ListScheduler.java
+++ b/src/main/java/com/seaofnodes/simple/ListScheduler.java
@@ -7,91 +7,157 @@ import java.util.*;
 
 public abstract class ListScheduler {
 
-    private static final BitSet VISIT = new BitSet();
-    private static int[] BCNTS;
-    public static void sched( CodeGen code ) {
-        assert VISIT.isEmpty();
-        BCNTS = new int[Node.UID()];
-        walk(code._start,VISIT);
-        VISIT.clear();
-    }
+    // eXtra per-node stuff for scheduling.
+    private static final IdentityHashMap<Node,XSched> XS = new IdentityHashMap<>();
+    private static class XSched {
+        static final Ary<XSched> FREE = new Ary<>(XSched.class);
+        static void alloc(CFGNode bb, Node n) {
+            XSched x = FREE.pop();
+            XS.put(n, (x==null ? new XSched() : x).init(bb,n));
+        }
+        void free() { _n = null; FREE.push(this); }
 
-    // Visit all CFG nodes
-    static void walk( CFGNode cfg, BitSet visit ) {
-        if( visit.get(cfg._nid) ) return;
-        visit.set(cfg._nid);
-        local(cfg);
-        for( Node n : cfg._outputs )
-            if( n instanceof CFGNode c )
-                walk(c,visit);
-    }
+        static XSched get(Node n) { return n==null ? null : XS.get(n); }
 
-    // Local schedule this one CFG
-    static void local( CFGNode bb ) {
-        if( !bb.blockHead() || bb instanceof StopNode ) return;
-        Node[] uses = bb._outputs._es;
-        int ulen = bb._outputs._len;
-
-        // Count block-locals
-        for( int i=0; i<ulen; i++ ) {
-            Node use = uses[i];
-            if( use.in(0)==bb && !(use instanceof PhiNode) ) {
-                // Normal basic block member: in(0)==bb and not a Phi
-                for( Node def : use._inputs )
-                    // Has defs from same block?  Then block-local inputs
-                    if( def != null && def.cfg0()==bb ) // Same block?
-                        BCNTS[use._nid]++;     // Raise block-local input count
+        private XSched init(CFGNode bb, Node n) {
+            _n = n;
+            _bcnt = 0;
+            _ruse = _rdef = _single = false;
+
+            // Count block-locals and remote inputs
+            if( !(n instanceof PhiNode) )
+                for( Node def : n._inputs )
+                    if( def != null && def != bb ) {
+                        if( def.cfg0()==bb ) _bcnt++; // Raise block-local input count
+                        else                 _ruse = true;
+                    }
+            // Count remote outputs and allowed registers
+            if( n instanceof MultiNode )
+                for( Node use : n._inputs )
+                    computeSingleRDef(bb,use);
+            else
+                computeSingleRDef(bb,n);
+            return this;
+        }
+
+        private void computeSingleRDef(CFGNode bb, Node n) {
+            RegMaskRW rmask = n instanceof MachNode mach ? mach.outregmap().copy() : null;
+            for( Node use : n._outputs ) {
+                // Remote use, so this is a remote def
+                if( use!=null && use.cfg0()!=bb ) _rdef = true;
+                // And mask between n's def mask and all n's users masks'
+                if( use instanceof MachNode mach && rmask != null )
+                    for( int i=1; i<use.nIns(); i++ )
+                        if( use.in(i)==n )
+                            rmask.and(mach.regmap(i));
             }
+            // Defines in a single register
+            _single = rmask!=null && rmask.size1();
+        }
+
+        // If _bcnt==0, declare ready; move user bcnts into rcnts.
+        boolean isReady() {
+            if( _bcnt > 0 || _rcnt > 0 ) return false;
+            if( _n instanceof MultiNode )
+                for( Node use : _n._outputs )
+                    if( use instanceof ProjNode ) readyUp(use);
+                    // anti-dep from a multireg directly
+                    else _readyUp(use);
+            else
+                readyUp(_n);
+            return true;
+        }
+        private static void readyUp(Node n) {
+            for( Node use : n._outputs )
+                _readyUp(use);
+        }
+        private static void _readyUp(Node use) {
+            XSched xs = get(use);
+            if( xs!=null && !(use instanceof PhiNode) )
+                { assert xs._bcnt>0; xs._bcnt--; xs._rcnt++; }
+        }
+
+        boolean decIsReady() {
+            assert _rcnt > 0;
+            _rcnt--;
+            return isReady();
         }
 
+        Node _n;         // Node this extra is for
+        int _bcnt;       // Not-ready not-scheduled inputs
+        int _rcnt;       // Ready not-scheduled inputs
+        boolean _ruse;   // Node IS a "remote use", uses a other-block value
+        boolean _rdef;   // Node IS a "remote def" of a value used in other block
+        boolean _single; // Defines a single register, likely to conflict
+    }
+
+
+    // List schedule every block
+    public static void sched( CodeGen code ) {
+        XS.clear();
+        for( CFGNode bb : code._cfg )
+            if( bb.blockHead() )
+                local(bb);
+    }
+
+    // Classic list scheduler
+    private static void local( CFGNode bb ) {
+        assert XS.isEmpty();
+        int len = bb.nOuts();
+
+        // Count block-locals, remote inputs and outputs
+        for( int i=0; i<len; i++ )
+            XSched.alloc(bb,bb.out(i));
+
         // Nodes are ready if they are not used by other nodes in this block.
-        // Move ready up front. We will never look at remaining nodes, later
-        // nodes are found by looking at users of ready nodes.
+        // Move ready up front.
         int ready = 0;
-        for( int i=0; i<ulen; i++ )
-            if( BCNTS[uses[i]._nid]==0 )   // No block-local inputs?
-                uses[ready++] = uses[i];   // Move into ready set
-        assert ready > 0;
+        for( int i=0; i<len; i++ )
+            if( XSched.get(bb.out(i)).isReady() ) // No block-local inputs?
+                bb._outputs.swap(ready++,i);      // Move into ready set
+        assert len==0 || ready > 0;
 
         // Classic list scheduler.  Behind sched is scheduled.  Between sched
         // and ready have zero counts and are ready to schedule.  Ahead of
         // ready is undefined.
         //
-        // As nodes are scheduled, the nodes they use decrement their _bcnt. Once
+        // As nodes are scheduled, the nodes they use decrement their bcnts[]. Once
         // that gets to 0, all the nodes using it are scheduled, so it's ready.
         int sched = 0;
-        while( sched < ulen ) {
-            assert sched < ready : "Scheduling nodes that are not ready. Probably due to duplicate nodes in the user list.";
-            int pick = best(uses, sched,ready); // Pick best
-            Node best = uses[pick];       // Swap best to head of ready
-            uses[pick] = uses[sched];
-            uses[sched++] = best; // And move it into the scheduled set
-            // Lower ready count of users
+        while( sched < len ) {
+            assert sched < ready;
+            int  pick = best(bb._outputs,sched,ready);  // Pick best
+            Node best = bb._outputs.swap(pick,sched++); // Swap best to head of ready and move into the scheduled set
+            // Lower ready count of users, and since projections are ready as
+            // soon as their multi is ready, lower those now too.
             for( Node use : best._outputs )
-                if( use instanceof ProjNode ) {
+                if( use instanceof ProjNode )
                     for( Node useuse : use._outputs )
                         ready = ready(bb,useuse,ready);
-                } else
-                    ready = ready(bb, use,ready);
+                else
+                    ready = ready(bb,use,ready);
         }
+
+        // Reset for next block
+        for( XSched x : XS.values() )
+            x.free();
+        XS.clear();
     }
 
     private static int ready(CFGNode bb, Node use, int ready) {
-        if( use != null && use.in(0)==bb && !(use instanceof PhiNode) ) {
-            assert BCNTS[use._nid] >= 1;
-            if( --BCNTS[use._nid] == 0 )
-                bb._outputs._es[ready++] = use; // Became ready, move into ready set
-        }
+        if( use!=null && !(use instanceof PhiNode) && use.in(0)==bb && XSched.get(use).decIsReady() )
+            bb._outputs.set(ready++, use); // Became ready, move into ready set
+            //bb._outputs.swap(ready++,use);  // Became ready, move into ready set
         return ready;
     }
 
 
     // Pick best between sched and ready.
-    private static int best( Node[] uses, int sched, int ready ) {
+    private static int best( Ary<Node> blk, int sched, int ready ) {
         int pick = sched;
-        int score = score(uses[pick]);
+        int score = score(blk.at(pick));
         for( int i=sched+1; i<ready; i++ ) {
-            int nscore = score(uses[i]);
+            int nscore = score(blk.at(i));
             if( nscore > score )
                 { score = nscore; pick = i; }
         }
@@ -99,12 +165,67 @@ public abstract class ListScheduler {
     }
 
     // Highest score wins.  Max at 1000, min at 10, except specials.
-    private static int score( Node n ) {
-        if( n.isMultiTail()  ) return 1001; // Pinned just behind the multi-head
-        if( n instanceof CFGNode ) return n instanceof ReturnNode ? 2 : 1; // Pinned at block exit
+    private static final int[] CNT = new int[3];
+    static int score( Node n ) {
+        if( n instanceof  ProjNode     ) return 1001; // Pinned at block entry
+        if( n instanceof CProjNode     ) return 1001; // Pinned at block entry
+        if( n instanceof   PhiNode     ) return 1000;
+        if( n instanceof CFGNode       ) return    1; // Pinned at block exit
+
+        int score = 500;
+        // Ideal nodes ignore register pressure scheduling
+        if( !(n instanceof MachNode) )
+            return score;
+
+        // Register pressure local scheduling: avoid overlapping specialized
+        // registers usages.
+
+        // Subtract 10 if this op forces a live range to exist that cannot be
+        // resolved immediately; i.e., live count goes up.  Scale to 20 if
+        // multi-def.
+
+        // Subtract 100 if this op forces a single-def live range to exist
+        // which might conflict on the same register with other live ranges.
+        // Defines a single register based on def & uses, and the output is not
+        // ready.  Scale to 200 for multi-def.
+        CNT[1]=CNT[2]=0;
+        XSched xn = XSched.get(n);
+        if( xn._rdef ) score = 200; // If defining a remote value, just generically stall alot
+        if( n instanceof MultiNode ) {
+            for( Node use : n._outputs )
+                singleUseNotReady( use, xn._single );
+        } else if( n.nOuts() == 1 )
+            singleUseNotReady( n, xn._single );
+        score +=  -10 * Math.min( CNT[1], 2 );
+        score += -100 * Math.min( CNT[2], 2 );
+
+        // Add 10 if this op ends a single-def live range, add 20 for 2 or more.
+        // Scale to 100,200 if the single-def is also single-register.
+        CNT[1]=CNT[2]=0;
+        for( int i=1; i<n.nIns(); i++ ) {
+            XSched xd = XSched.get( n.in(i) );
+            if( xd != null && xd._n.nOuts()==1 )
+                CNT[xd._single || ((MachNode)n).regmap(i).size1() ? 2 : 1]++;
+        }
+        score +=   10 * Math.min( CNT[1], 2 );
+        score +=  100 * Math.min( CNT[2], 2 );
+
+        //// Nothing special
+        //if( n instanceof Pe            ) return  500; // RISC want to go after PE
+        //if( n instanceof Risc          ) return  400; // RISC want to go after PE
+        assert 10 <= score && score <= 990;
+        return score;
+    }
 
-        // Nothing special
-        return 500;
+    // Single use, and that use is not ready to fire once this one does.
+    // If true, stalling 'n' might reduce 'n's lifetime.
+    // Return 0 for false, 1 if true, 10 if also single register
+    private static void singleUseNotReady( Node n, boolean single ) {
+        if( n.nOuts() != 1 ) return;
+        XSched xu = XSched.get(n.out(0));
+        if( xu !=null && xu._bcnt==0 )
+            return;
+        CNT[single ? 2 : 1]++;
     }
 
 }
diff --git a/src/main/java/com/seaofnodes/simple/Machine.java b/src/main/java/com/seaofnodes/simple/Machine.java
new file mode 100644
index 00000000..b29e9aba
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/Machine.java
@@ -0,0 +1,21 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.node.CFGNode;
+import com.seaofnodes.simple.node.IfNode;
+import com.seaofnodes.simple.node.Node;
+
+abstract public class Machine {
+    // Human readable machine name.  Something like "x86-64" or "arm" or "risc5"
+    public abstract String name();
+    // Human-readable name for a register number, e.g. "RAX" or "R0"
+    public abstract String reg( int reg );
+    // Create a split op; any register to any register, including stack slots
+    public abstract Node split();
+    // Return a MachNode unconditional branch
+    public abstract CFGNode jump();
+    // Break an infinite loop
+    public abstract IfNode never( CFGNode ctrl );
+    // Instruction select from ideal nodes
+    public abstract Node instSelect( Node n );
+}
diff --git a/src/main/java/com/seaofnodes/simple/Parser.java b/src/main/java/com/seaofnodes/simple/Parser.java
index c16e3267..61a53d68 100644
--- a/src/main/java/com/seaofnodes/simple/Parser.java
+++ b/src/main/java/com/seaofnodes/simple/Parser.java
@@ -2,6 +2,7 @@ package com.seaofnodes.simple;
 
 import com.seaofnodes.simple.node.*;
 import com.seaofnodes.simple.type.*;
+import java.text.ParseException;
 import java.util.*;
 
 /**
@@ -13,23 +14,12 @@ import java.util.*;
  */
 public class Parser {
 
-    /**
-     * A Global Static, unique to each compilation.  This is a public, so we
-     * can make constants everywhere without having to thread the StartNode
-     * through the entire parser and optimizer.
-     * <p>
-     * To make the compiler multithreaded, this field will have to move into a TLS.
-     */
-    public static StartNode START;
-
     public static ConstantNode ZERO; // Very common node, cached here
     public static ConstantNode NIL;  // Very common node, cached here
     public static XCtrlNode XCTRL;   // Very common node, cached here
 
-    // Next available memory alias number
-    static int ALIAS;
-
-    public StopNode STOP;
+    // Compile driver
+    public final CodeGen _code;
 
     // The Lexer.  Thin wrapper over a byte[] buffer with a cursor.
     private final Lexer _lexer;
@@ -51,7 +41,7 @@ public class Parser {
     /**
      * List of keywords disallowed as identifiers
      */
-    private static final HashSet<String> KEYWORDS = new HashSet<>(){{
+    public static final HashSet<String> KEYWORDS = new HashSet<>(){{
             add("bool");
             add("break");
             add("byte");
@@ -98,21 +88,14 @@ public class Parser {
     public final HashMap<String, StructNode> INITS;
 
 
-    public Parser(String source) { this(source, TypeInteger.BOT); }
-
-    public Parser(String source, TypeInteger arg) {
-        Node.reset();
-        IterPeeps.reset();
-        Type.reset();
-        _lexer = new Lexer(source);
+    public Parser(CodeGen code, TypeInteger arg) {
+        _code = code;
+        _lexer = new Lexer(code._src);
         _scope = new ScopeNode();
         _continueScope = _breakScope = null;
-        START = new StartNode(arg);
-        STOP = new StopNode(source);
         ZERO  = con(TypeInteger.ZERO).keep();
         NIL  = con(Type.NIL).keep();
         XCTRL= new XCtrlNode().peephole().keep();
-        ALIAS = 2; // alias 0 for the control, 1 for memory
         TYPES = defaultTypes();
         INITS = new HashMap<>();
     }
@@ -142,13 +125,13 @@ public class Parser {
     }
 
     // Debugging utility to find a Node by index
-    public static Node find(int nid) { return START.find(nid); }
+    public Node f(int nid) { return _code.f(nid); }
 
     private Node ctrl() { return _scope.ctrl(); }
     private <N extends Node> N ctrl(N n) { return _scope.ctrl(n); }
 
-    public StopNode parse() { return parse(false); }
-    public StopNode parse(boolean show) {
+    public void parse() { parse(false); }
+    public void parse(boolean show) {
         _xScopes.push(_scope);
         _scope.define(ScopeNode.CTRL, Type.CONTROL   , false, null, _lexer);
         _scope.define(ScopeNode.MEM0, TypeMem.BOT    , false, null, _lexer);
@@ -158,7 +141,8 @@ public class Parser {
         _scope.mem(new MemMergeNode(false));
 
         // Parse whole program, as-if function header "{ int arg -> body }"
-        parseFunctionBody(TypeFunPtr.MAIN,loc(),"arg");
+        parseFunctionBody(_code._main,loc(),"arg");
+        _code.link(_code._main)._name = "main";
 
         if( !_lexer.isEOF() ) throw _errorSyntax("unexpected");
 
@@ -168,9 +152,8 @@ public class Parser {
         for( StructNode init : INITS.values() )
             init.unkeep().kill();
         INITS.clear();
-        STOP.peephole();
+        _code._stop.peephole();
         if( show ) showGraph();
-        return STOP;
     }
 
     /**
@@ -184,24 +167,24 @@ public class Parser {
         ScopeNode breakScope = _breakScope; _breakScope = null;
         ScopeNode continueScope = _continueScope; _continueScope = null;
 
-        FunNode fun = _fun = (FunNode)peep(new FunNode(loc(),START,sig));
+        FunNode fun = _fun = (FunNode)peep(new FunNode(loc(),sig,null,_code._start));
         // Once the function header is available, install in linker table -
         // allowing recursive functions.  Linker matches on declared args and
         // exact fidx, and ignores the return (because the fidx will only match
         // the exact single function).
-        CodeGen.CODE.link(fun);
+        _code.link(fun);
 
         Node rpc = new ParmNode("$rpc",0,TypeRPC.BOT,fun,con(TypeRPC.BOT)).peephole();
 
         // Build a multi-exit return point for all function returns
-        RegionNode r = new RegionNode((Node)null,null).init();
+        RegionNode r = new RegionNode((Lexer)null,null,null).init();
         assert r.inProgress();
         PhiNode rmem = new PhiNode(ScopeNode.MEM0,TypeMem.BOT,r,null).init();
         PhiNode rrez = new PhiNode(ScopeNode.ARG0,Type.BOTTOM,r,null).init();
         ReturnNode ret = new ReturnNode(r, rmem, rrez, rpc, fun).init();
         fun.setRet(ret);
         assert ret.inProgress();
-        STOP.addDef(ret);
+        _code._stop.addDef(ret);
 
         // Pre-call the function from Start, with worse-case arguments.  This
         // represents all the future, yet-to-be-parsed functions calls and
@@ -400,7 +383,7 @@ public class Parser {
         // Our current scope is the body Scope
         ctrl(ifT.unkeep());     // set ctrl token to ifTrue projection
         _scope.addGuards(ifT,pred.unkeep(),false); // Up-cast predicate
-        Node expr = parseStatement().keep();       // Parse loop body
+        parseStatement();       // Parse loop body
         _scope.removeGuards(ifT);
 
         // Merge the loop bottom into other continue statements
@@ -440,7 +423,7 @@ public class Parser {
         _xScopes.pop();
         _xScopes.push(exit);
         _scope = exit;
-        return peep(expr.unkeep());
+        return ZERO;
     }
 
     private ScopeNode jumpTo(ScopeNode toScope) {
@@ -598,7 +581,7 @@ public class Parser {
      * @return {@code null}
      */
     Node showGraph() {
-        System.out.println(new GraphVisualizer().generateDotOutput(STOP,_scope,_xScopes));
+        System.out.println(new GraphVisualizer().generateDotOutput(_code._stop,_scope,_xScopes));
         return null;
     }
 
@@ -687,7 +670,6 @@ public class Parser {
         boolean hasBang = match("!");
         Lexer loc = loc();
         String name = requireId();
-
         // Optional initializing expression follows
         boolean xfinal = false;
         Node expr;
@@ -711,7 +693,7 @@ public class Parser {
                 if( !xfinal ) t = t.glb();  // Widen if not final
             }
             if( t instanceof TypeFunPtr && expr._type instanceof TypeFunPtr tfp && tfp.isConstant() )
-                tfp.setName(name);
+                _code.link(tfp)._name = name;
 
         } else {
             // Need an expression to infer the type.
@@ -779,7 +761,7 @@ public class Parser {
             s.addDef(_scope.in(i));
             Var v = _scope._vars.at(i);
             if( !v.isFRef() )  // Promote to outer scope, not defined here
-                fs.push(Field.make(v._name,v.type(),ALIAS++,v._final));
+                fs.push(Field.make(v._name,v.type(),_code.getALIAS(),v._final));
         }
         TypeStruct ts = s._ts = TypeStruct.make(typeName, fs.asAry());
         TYPES.put(typeName, TypeMemPtr.make(ts));
@@ -835,7 +817,7 @@ public class Parser {
         int old2 = pos();
         match("!");
         String id = _lexer.matchId();
-        if( !(peek(',') || peek(';')) )
+        if( !(peek(',') || peek(';') || match("->")) )
             return posT(old1);
         pos(old2);              // Reset lexer to reparse
         if( id==null )
@@ -853,7 +835,7 @@ public class Parser {
         Type ta = TYPES.get(tname);
         if( ta != null ) return (TypeMemPtr)ta;
         // Need make an array type.
-        TypeStruct ts = TypeStruct.makeAry(TypeInteger.BOT,ALIAS++,t,ALIAS++);
+        TypeStruct ts = TypeStruct.makeAry(TypeInteger.U32,_code.getALIAS(),t,_code.getALIAS());
         assert ts.str().equals(tname);
         TypeMemPtr tary = TypeMemPtr.make(ts);
         TYPES.put(tname,tary);
@@ -1204,20 +1186,29 @@ public class Parser {
         if( fs==null )
             throw error("Unknown struct type '" + obj._name + "'");
         int len = fs.length;
-        Node[] ns = new Node[2+len+len];
+        Node[] ns = new Node[2+len];
         ns[0] = ctrl();         // Control in slot 0
         // Total allocated length in bytes
         ns[1] = size;
         // Memory aliases for every field
         for( int i = 0; i < len; i++ )
-            ns[2    +i] = memAlias(fs[i]._alias);
-        // Initial values for every field
-        for( int i = 0; i < len; i++ )
-            ns[2+len+i] = init.get(i+idx);
-        Node nnn = new NewNode(TypeMemPtr.make(obj), ns).peephole();
+            ns[2+i] = memAlias(fs[i]._alias);
+        Node nnn = new NewNode(TypeMemPtr.make(obj), ns).peephole().keep();
         for( int i = 0; i < len; i++ )
             memAlias(fs[i]._alias, new ProjNode(nnn,i+2,memName(fs[i]._alias)).peephole());
-        return new ProjNode(nnn,1,obj._name).peephole();
+        Node ptr = new ProjNode(nnn.unkeep(),1,obj._name).peephole().keep();
+
+        // Initial nonzero values for every field
+        for( int i = 0; i < len; i++ ) {
+            Node val = init.get( i + idx );
+            if( val._type != val._type.makeZero() ) {
+                Node mem = memAlias(fs[i]._alias);
+                Node st = new StoreNode(loc(),fs[i]._fname,fs[i]._alias,fs[i]._type,mem,ptr,con(obj.offset(i)),val,true).peephole();
+                memAlias(fs[i]._alias,st);
+            }
+        }
+
+        return ptr.unkeep();
     }
 
     private static final Ary<Node> ALTMP = new Ary<>(Node.class);
@@ -1261,8 +1252,9 @@ public class Parser {
             throw error("Accessing unknown field '" + name + "' from 'null'");
 
         // Sanity check expr for being a reference
-        if( !(expr._type instanceof TypeMemPtr ptr) )
-            throw error("Expected reference but got " + expr._type.str());
+        if( !(expr._type instanceof TypeMemPtr ptr) ) {
+            throw error( "Expected "+(name=="#" || name=="[]" ? "array" : "reference")+" but found " + expr._type.str() );
+        }
 
         // Sanity check field name for existing
         TypeMemPtr tmp = (TypeMemPtr)TYPES.get(ptr._obj._name);
@@ -1302,7 +1294,7 @@ public class Parser {
         // Arrays include control, as a proxy for a safety range check
         // Structs don't need this; they only need a NPE check which is
         // done via the type system.
-        if( base.isAry() ) load.setDef(0,ctrl());
+        if( base.isAry() && !name.equals("#") ) load.setDef(0,ctrl());
         load = peep(load);
 
         // Check for assign-update, "ptr.fld += expr" or "ary[idx]++"
@@ -1366,7 +1358,7 @@ public class Parser {
         }
         require("->");
         // Make a concrete function type, with a fidx
-        TypeFunPtr tfp = TypeFunPtr.makeFun(TypeTuple.make(ts.asAry()),Type.BOTTOM);
+        TypeFunPtr tfp = _code.makeFun(TypeTuple.make(ts.asAry()),Type.BOTTOM);
         ReturnNode ret = parseFunctionBody(tfp,loc,ids.asAry());
         return con(ret._fun.sig());
     }
@@ -1400,6 +1392,14 @@ public class Parser {
         // Unkeep them all
         for( Node arg : args )
             arg.unkeep();
+        // Dead into the call?  Skip all the node gen
+        if( ctrl()._type == Type.XCONTROL ) {
+            for( Node arg : args )
+                if( arg.isUnused() )
+                    arg.kill();
+            return con(Type.TOP);
+        }
+
         // Into the call
         CallNode call = (CallNode)new CallNode(loc(), args.asAry()).peephole();
 
@@ -1656,7 +1656,6 @@ public class Parser {
         private String parseNumberString() {
             int old = _position;
             int len = Math.abs(isLongOrDouble());
-            _position += len;
             return new String(_input,old,len);
         }
 
diff --git a/src/main/java/com/seaofnodes/simple/RegMask.java b/src/main/java/com/seaofnodes/simple/RegMask.java
new file mode 100644
index 00000000..20be7157
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/RegMask.java
@@ -0,0 +1,39 @@
+package com.seaofnodes.simple;
+
+import java.util.BitSet;
+
+// A "register mask" - 1 bit set for each allowed register.  In addition "stack
+// slot" registers may be allowed, effectively making the set infinite.
+public class RegMask {
+
+    public static final RegMask EMPTY = new RegMask();
+
+    final BitSet _bits;
+
+    public RegMask(long   x ) { _bits = BitSet.valueOf(new long[]{x}); }
+    public RegMask(long[] xs) { _bits = BitSet.valueOf(           xs); }
+    // Internal constructor
+    RegMask() { _bits = new BitSet(); }
+    RegMask(BitSet bs) { _bits = bs; }
+
+    public boolean get(int r) { return _bits.get(r); }
+
+    // Defensive writable copy
+    public RegMaskRW copy() { return new RegMaskRW( (BitSet)_bits.clone() ); }
+
+    boolean size1() { return _bits.cardinality()==1; }
+}
+
+class RegMaskRW extends RegMask {
+    public RegMaskRW() { super(); }
+    public RegMaskRW(long x) { super(new long[]{x}); }
+    public RegMaskRW(long[] xs) { super(xs); }
+    public RegMaskRW(BitSet bs) { super(bs); }
+    public void set(int r) { _bits.set(r); }
+    public void clr(int r) { _bits.clear(r); }
+    public void set(int r, boolean b) { _bits.set(r,b); }
+    public RegMaskRW and( RegMask r ) {
+        _bits.and(r._bits);
+        return this;
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/SB.java b/src/main/java/com/seaofnodes/simple/SB.java
index 6f5a29ee..7d580c21 100644
--- a/src/main/java/com/seaofnodes/simple/SB.java
+++ b/src/main/java/com/seaofnodes/simple/SB.java
@@ -29,6 +29,23 @@ public final class SB {
   public SB p( int    s ) { _sb.append(s); return this; }
   public SB p( long   s ) { _sb.append(s); return this; }
   public SB p( boolean s) { _sb.append(s); return this; }
+  // 4 hex digits
+  public SB hex4(int s) {
+    assert (s>>4*4)==0; // Fits in 16 bits
+    for( int i=0; i<4; i++ ) {
+      int digit = (s>>((3-i)*4)) & 0xf;
+      _sb.append((char)((digit <= 9 ? '0' : ('A'-10))+digit));
+    }
+    return this;
+  }
+  // Fixed width field
+  public SB fix( int sz, String s ) {
+    assert sz >=0;
+    for( int i=0; i<sz; i++ )
+      _sb.append( i < s.length() ? s.charAt(i) : ' ');
+    return this;
+  }
+
   // Not spelled "p" on purpose: too easy to accidentally say "p(1.0)" and
   // suddenly call the autoboxed version.
   public SB pobj( Object s ) { _sb.append(s.toString()); return this; }
diff --git a/src/main/java/com/seaofnodes/simple/node/AddNode.java b/src/main/java/com/seaofnodes/simple/node/AddNode.java
index e6704ea6..6b7f2418 100644
--- a/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -4,6 +4,8 @@ import com.seaofnodes.simple.type.*;
 
 import java.util.BitSet;
 
+import static com.seaofnodes.simple.Parser.con;
+
 public class AddNode extends Node {
     public AddNode(Node lhs, Node rhs) { super(null, lhs, rhs); }
 
@@ -53,7 +55,7 @@ public class AddNode extends Node {
 
         // Add of same to a multiply by 2
         if( lhs==rhs )
-            return new MulNode(lhs,new ConstantNode(TypeInteger.constant(2)).peephole());
+            return new ShlNode(null,lhs,con(1));
 
         // Goal: a left-spine set of adds, with constants on the rhs (which then fold).
 
@@ -126,6 +128,7 @@ public class AddNode extends Node {
             lphi = pcon(lhs.in(2),op); // Will rotate with the Phi push
         }
         if( lphi==null ) return null;
+        if( lphi.region().nIns() <=2 ) return null; // Phi is collapsing
 
         // RHS is a constant or a Phi of constants
         if( !(rhs instanceof ConstantNode) && pcon(rhs,op)==null )
diff --git a/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index ae968ca1..84be11a9 100644
--- a/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -3,7 +3,6 @@ package com.seaofnodes.simple.node;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.Utils;
 import com.seaofnodes.simple.type.*;
-
 import java.util.BitSet;
 import static com.seaofnodes.simple.type.TypeInteger.*;
 
@@ -13,7 +12,7 @@ abstract public class BoolNode extends Node {
         super(null, lhs, rhs);
     }
 
-    abstract String op();       // String opcode name
+    abstract public String op(); // String opcode name
 
     @Override
     public String label() { return getClass().getSimpleName(); }
@@ -37,14 +36,14 @@ abstract public class BoolNode extends Node {
             return BOOL.dual();
         if( in(1)==in(2) )
             // LT fails, both EQ and LE succeed
-            return this instanceof LT ? TypeInteger.FALSE : TypeInteger.TRUE;
+            return this instanceof LT ? FALSE : TRUE;
         if( t1 instanceof TypeInteger i1 &&
             t2 instanceof TypeInteger i2 )
             return doOp(i1,i2);
         if( t1 instanceof TypeFloat f1 &&
             t2 instanceof TypeFloat f2 &&
             f1.isConstant() && f2.isConstant() )
-            return doOp(f1.value(), f2.value()) ? TypeInteger.TRUE : TypeInteger.FALSE;
+            return doOp(f1.value(), f2.value()) ? TRUE : FALSE;
         return BOOL;
     }
 
@@ -56,7 +55,7 @@ abstract public class BoolNode extends Node {
     public Node idealize() {
         // Compare of same
         if( in(1)==in(2) )
-            return this instanceof LT ? Parser.ZERO : new ConstantNode(TypeInteger.TRUE);
+            return this instanceof LT ? Parser.ZERO : new ConstantNode(TRUE);
 
         // Equals pushes constant to the right; 5==X becomes X==5.
         if( this instanceof EQ ) {
@@ -82,7 +81,7 @@ abstract public class BoolNode extends Node {
 
     public static class EQ extends BoolNode {
         public EQ(Node lhs, Node rhs) { super(lhs,rhs); }
-        String op() { return "=="; }
+        public String op() { return "=="; }
         TypeInteger doOp(TypeInteger i1, TypeInteger i2) {
             if( i1==i2 && i1.isConstant() ) return TRUE;
             if( i1._max < i2._min || i1._min > i2._max ) return FALSE;
@@ -93,7 +92,7 @@ abstract public class BoolNode extends Node {
     }
     public static class LT extends BoolNode {
         public LT(Node lhs, Node rhs) { super(lhs,rhs); }
-        String op() { return "<" ; }
+        public String op() { return "<" ; }
         public String glabel() { return "&lt;"; }
         TypeInteger doOp(TypeInteger i1, TypeInteger i2) {
             if( i1._max <  i2._min ) return TRUE;
@@ -105,7 +104,7 @@ abstract public class BoolNode extends Node {
     }
     public static class LE extends BoolNode {
         public LE(Node lhs, Node rhs) { super(lhs,rhs); }
-        String op() { return "<="; }
+        public String op() { return "<="; }
         public String glabel() { return "&lt;="; }
         TypeInteger doOp(TypeInteger i1, TypeInteger i2) {
             if( i1._max <= i2._min ) return TRUE;
@@ -120,4 +119,16 @@ abstract public class BoolNode extends Node {
     public static class LTF extends LT { public LTF(Node lhs, Node rhs) { super(lhs,rhs); } boolean doOp(double lhs, double rhs) { return lhs <  rhs; } }
     public static class LEF extends LE { public LEF(Node lhs, Node rhs) { super(lhs,rhs); } boolean doOp(double lhs, double rhs) { return lhs <= rhs; } }
 
+    // Unsigned less that, for range checks.  Not directly user writable.
+    public static class ULT extends BoolNode {
+        public ULT(Node lhs, Node rhs) { super(lhs,rhs); }
+        public String op() { return "u<" ; }
+        public String glabel() { return "u&lt;"; }
+        TypeInteger doOp(TypeInteger i1, TypeInteger i2) {
+            if( Long.compareUnsigned(i1._max,i2._min) <  0 ) return TRUE;
+            if( Long.compareUnsigned(i1._min,i2._max) >= 0 ) return FALSE;
+            return BOOL;
+        }
+        Node copy(Node lhs, Node rhs) { return new ULT(lhs,rhs); }
+    }
 }
diff --git a/src/main/java/com/seaofnodes/simple/node/CFGNode.java b/src/main/java/com/seaofnodes/simple/node/CFGNode.java
index b051b3ce..174725f5 100644
--- a/src/main/java/com/seaofnodes/simple/node/CFGNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CFGNode.java
@@ -1,12 +1,12 @@
 package com.seaofnodes.simple.node;
 
+import com.seaofnodes.simple.Ary;
 import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.type.*;
 import com.seaofnodes.simple.Utils;
-
+import com.seaofnodes.simple.type.*;
 import java.util.BitSet;
-import java.util.HashSet;
 import java.util.HashMap;
+import java.util.HashSet;
 
 /** Control Flow Graph Nodes
  * <p>
@@ -21,7 +21,13 @@ import java.util.HashMap;
  */
 public abstract class CFGNode extends Node {
 
-    public CFGNode(Node... nodes) { super(nodes); }
+    public CFGNode(Node...   nodes) { super(nodes); }
+    public CFGNode(CFGNode cfg) {
+        super(cfg);
+        _idepth = cfg._idepth;
+        _ltree = cfg._ltree;
+        _pre = cfg._pre;
+    }
 
     public CFGNode cfg(int idx) { return (CFGNode)in(idx); }
 
@@ -101,8 +107,8 @@ public abstract class CFGNode extends Node {
         _pre = pre++;
         // Pre-walk
         for( Node use : _outputs )
-            if( use instanceof CFGNode usecfg && !skip(usecfg) )
-                pre = usecfg._bltWalk(pre,use instanceof FunNode fuse ? fuse : fun,stop,post);
+            if( use instanceof CFGNode usecfg && !skip( usecfg ) )
+                pre = usecfg._bltWalk( pre, use instanceof FunNode fuse ? fuse : fun, stop, post );
 
         // Post-order work: find innermost loop
         LoopTree inner = null, ltree;
diff --git a/src/main/java/com/seaofnodes/simple/node/CProjNode.java b/src/main/java/com/seaofnodes/simple/node/CProjNode.java
index 01119310..690ef590 100644
--- a/src/main/java/com/seaofnodes/simple/node/CProjNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CProjNode.java
@@ -6,7 +6,7 @@ import com.seaofnodes.simple.type.TypeMem;
 import com.seaofnodes.simple.type.TypeTuple;
 import java.util.BitSet;
 
-public class CProjNode extends CFGNode implements MultiUse {
+public class CProjNode extends CFGNode {
 
     // Which slice of the incoming multipart value
     public final int _idx;
@@ -19,9 +19,9 @@ public class CProjNode extends CFGNode implements MultiUse {
         _idx = idx;
         _label = label;
     }
+    public CProjNode(CProjNode c) { super(c); _idx = c._idx; _label = c._label; }
 
     @Override public String label() { return _label; }
-    @Override public int idx() { return _idx; }
 
     @Override StringBuilder _print1(StringBuilder sb, BitSet visited) { return sb.append(_label); }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/CallEndNode.java b/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
index 07a2b5a3..4e50c1fc 100644
--- a/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
@@ -1,8 +1,6 @@
 package com.seaofnodes.simple.node;
 
-import com.seaofnodes.simple.IterPeeps;
-import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.Utils;
+import com.seaofnodes.simple.*;
 import com.seaofnodes.simple.type.*;
 import java.util.BitSet;
 
@@ -14,7 +12,8 @@ public class CallEndNode extends CFGNode implements MultiNode {
     // When set true, this Call/CallEnd/Fun/Return is being trivially inlined
     private boolean _folding;
 
-    public CallEndNode(CallNode call) { super(call); }
+    public CallEndNode(CallNode call) { super(new Node[]{call}); }
+    public CallEndNode(CallEndNode cend) { super(cend); }
 
     @Override
     public String label() { return "CallEnd"; }
@@ -46,8 +45,7 @@ public class CallEndNode extends CFGNode implements MultiNode {
 
         // Trivial inlining: call site calls a single function; single function
         // is only called by this call site.
-        if( !_folding && nIns()==2 ) {
-            CallNode call = call();
+        if( !_folding && nIns()==2 && in(0) instanceof CallNode call ) {
             Node fptr = call.fptr();
             if( fptr.nOuts() == 1 && // Only user is this call
                 fptr instanceof ConstantNode && // We have an immediate call
@@ -72,7 +70,7 @@ public class CallEndNode extends CFGNode implements MultiNode {
                         fun.setDef(1,Parser.XCTRL); // No default/unknown StartNode caller
                         fun.setDef(2,call.ctrl());  // Bypass the Call;
                         fun.ret().setDef(3,null);   // Return is folding also
-                        IterPeeps.addAll(fun._outputs);
+                        CodeGen.CODE.addAll(fun._outputs);
                         return this;
                     }
                 } else {
diff --git a/src/main/java/com/seaofnodes/simple/node/CallNode.java b/src/main/java/com/seaofnodes/simple/node/CallNode.java
index 246398ee..a9ca852c 100644
--- a/src/main/java/com/seaofnodes/simple/node/CallNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CallNode.java
@@ -17,17 +17,14 @@ public class CallNode extends CFGNode {
     public final Parser.Lexer _loc;
 
     public CallNode(Parser.Lexer loc, Node... nodes) { super(nodes); _loc = loc; }
+    public CallNode(CallNode call) { super(call); _loc = call._loc; }
 
     @Override
     public String label() { return "Call"; }
 
-    @Override
-    StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        String fname = null;
-        Node fptr = fptr();
-        if( fptr._type instanceof TypeFunPtr tfp && tfp.isConstant() )
-            fname = tfp._name;
-        if( fname==null ) fptr._print0(sb,visited);
+    @Override StringBuilder _print1(StringBuilder sb, BitSet visited) {
+        String fname = name();
+        if( fname == null ) fptr()._print0(sb,visited);
         else sb.append(fname);
         sb.append("( ");
         for( int i=2; i<nIns()-1; i++ )
@@ -35,6 +32,13 @@ public class CallNode extends CFGNode {
         sb.setLength(sb.length()-1);
         return sb.append(")");
     }
+    public String name() {
+        if( fptr()._type instanceof TypeFunPtr tfp && tfp.isConstant() )
+            return CodeGen.CODE.link(tfp)._name;
+        return null;
+    }
+
+
 
     Node ctrl() { return in(0); }
     Node mem () { return in(1); }
@@ -118,7 +122,7 @@ public class CallNode extends CFGNode {
             if( use instanceof ParmNode parm )
                 parm.addDef(parm._idx==0 ? cend() : arg(parm._idx));
         // Call end points to function return
-        IterPeeps.add(cend()).addDef(fun.ret());
+        CodeGen.CODE.add(cend()).addDef(fun.ret());
         assert linked(fun);
     }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/ConstantNode.java b/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
index e03bfb0e..d788cff7 100644
--- a/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ConstantNode.java
@@ -1,9 +1,10 @@
 package com.seaofnodes.simple.node;
 
+import com.seaofnodes.simple.CodeGen;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.SB;
 import com.seaofnodes.simple.type.Type;
-
+import com.seaofnodes.simple.type.TypeFunPtr;
 import java.util.BitSet;
 
 /**
@@ -18,12 +19,14 @@ import java.util.BitSet;
  * <p>
  * The Constant's value is the value stored in it.
  */
+
 public class ConstantNode extends Node {
     public final Type _con;
     public ConstantNode( Type type ) {
-        super(Parser.START);
-        _con = type;
+        super(new Node[]{CodeGen.CODE._start});
+        _con = _type = type;
     }
+    public ConstantNode( ConstantNode con ) { super(con);  _con = con._type;  }
 
     public static Node make( Type type ) {
         if( type==Type. CONTROL ) return new CtrlNode();
@@ -39,6 +42,11 @@ public class ConstantNode extends Node {
 
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
+        if( _con instanceof TypeFunPtr tfp ) {
+            FunNode fun = CodeGen.CODE.link(tfp);
+            if( fun._name != null )
+                return sb.append("{ ").append(fun._name).append("}");
+        }
         return sb.append(_con.print(new SB()));
     }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/CtrlNode.java b/src/main/java/com/seaofnodes/simple/node/CtrlNode.java
index 162417bb..0ea060bd 100644
--- a/src/main/java/com/seaofnodes/simple/node/CtrlNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CtrlNode.java
@@ -1,11 +1,12 @@
 package com.seaofnodes.simple.node;
 
+import com.seaofnodes.simple.CodeGen;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.type.Type;
 import java.util.BitSet;
 
 public class CtrlNode extends CFGNode {
-    public CtrlNode() { super(Parser.START); }
+    public CtrlNode() { super(CodeGen.CODE._start); }
     @Override public String label() { return "Ctrl"; }
     @Override StringBuilder _print1(StringBuilder sb, BitSet visited) { return sb.append("Cctrl"); }
     @Override public boolean isConst() { return true; }
diff --git a/src/main/java/com/seaofnodes/simple/node/FunNode.java b/src/main/java/com/seaofnodes/simple/node/FunNode.java
index 1f0c76eb..506e7758 100644
--- a/src/main/java/com/seaofnodes/simple/node/FunNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/FunNode.java
@@ -4,6 +4,7 @@ import com.seaofnodes.simple.*;
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeFunPtr;
 import java.util.BitSet;
+import static com.seaofnodes.simple.CodeGen.CODE;
 
 public class FunNode extends RegionNode {
 
@@ -13,10 +14,13 @@ public class FunNode extends RegionNode {
     private TypeFunPtr _sig;    // Initial signature
     private ReturnNode _ret;    // Return pointer
 
-    public FunNode( Parser.Lexer loc, StartNode start, TypeFunPtr sig ) { super(loc,null,start); _sig=sig; }
+    public String _name;        // Debug name
+
+    public FunNode( Parser.Lexer loc, TypeFunPtr sig, Node... nodes ) { super(loc,nodes); _sig = sig; }
+    public FunNode( FunNode fun ) { super( fun, fun._loc ); _sig = fun.sig(); _name = fun._name; }
 
     @Override
-    public String label() { return _sig._name == null ? "$fun" : _sig._name; }
+    public String label() { return _name == null ? "$fun" : _name; }
 
     // Find the one CFG user from Fun.  It's not always the Return, but always
     // the Return *is* a CFG user of Fun.
@@ -45,9 +49,10 @@ public class FunNode extends RegionNode {
     public TypeFunPtr sig() { return _sig; }
     void setSig( TypeFunPtr sig ) {
         assert sig.isa(_sig);
-        if( _sig != sig )
-            IterPeeps.add(this);
-        _sig = sig;
+        if( _sig != sig ) {
+            CODE.add(this);
+            _sig = sig;
+        }
     }
 
     @Override
@@ -58,6 +63,15 @@ public class FunNode extends RegionNode {
 
     @Override
     public Node idealize() {
+
+        // Some linked path dies
+        Node progress = deadPath();
+        if( progress!=null ) {
+            if( nIns()==3 && in(2) instanceof CallNode call )
+                CODE.add(call.cend()); // If Start and one call, check for inline
+            return progress;
+        }
+
         // When can we assume no callers?  Or no other callers (except main)?
         // In a partial compilation, we assume Start gets access to any/all
         // top-level public structures and recursively what they point to.
@@ -66,16 +80,18 @@ public class FunNode extends RegionNode {
         // In a total compilation, we can start from Start and keep things
         // more contained.
 
-
         // If no default/unknown caller, use the normal RegionNode ideal rules
         // to collapse
         if( unknownCallers() ) return null;
-        Node progress = super.idealize();
-        if( progress!=null ) {
-            IterPeeps.add( CodeGen.CODE._stop);
-            IterPeeps.add( _ret );
+
+        // If down to a single input, become that input
+        if( nIns()==2 && !hasPhi() ) {
+            CODE.add( CODE._stop ); // Stop will remove dead path
+            CODE.add( _ret );       // Return will compute to TOP control
+            return in(1); // Collapse if no Phis; 1-input Phis will collapse on their own
         }
-        return progress;
+
+        return null;
     }
 
     // Bypass Region idom, always assume depth == 1, one more than Start
diff --git a/src/main/java/com/seaofnodes/simple/node/IfNode.java b/src/main/java/com/seaofnodes/simple/node/IfNode.java
index eafcdf5b..9e6d2dff 100644
--- a/src/main/java/com/seaofnodes/simple/node/IfNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/IfNode.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple.node;
 
+import com.seaofnodes.simple.CodeGen;
 import com.seaofnodes.simple.IterPeeps;
 import com.seaofnodes.simple.type.*;
 import java.util.BitSet;
@@ -9,8 +10,9 @@ public class IfNode extends CFGNode implements MultiNode {
 
     public IfNode(Node ctrl, Node pred) {
         super(ctrl, pred);
-        IterPeeps.add(this);    // Because idoms are complex, just add it
+        CodeGen.CODE.add(this); // Because idoms are complex, just add it
     }
+    public IfNode(IfNode iff) { super(iff); }
 
     @Override
     public String label() { return "If"; }
@@ -34,7 +36,6 @@ public class IfNode extends CFGNode implements MultiNode {
         // If the If node is not reachable then neither is any following Proj
         if (ctrl()._type != Type.CONTROL && ctrl()._type != Type.BOTTOM )
             return TypeTuple.IF_NEITHER;
-        if( _disablePeephole ) return TypeTuple.IF_BOTH;
         Node pred = pred();
         Type t = pred._type;
         // High types mean NEITHER side is reachable.
@@ -59,7 +60,7 @@ public class IfNode extends CFGNode implements MultiNode {
         if( !pred()._type.isHighOrConst() )
             for( CFGNode dom = idom(), prior=this; dom!=null;  prior = dom, dom = dom.idom() )
                 if( dom.addDep(this) instanceof IfNode iff && iff.pred().addDep(this)==pred() && prior instanceof CProjNode prj ) {
-                    setDef(1,new ConstantNode(TypeInteger.constant(prj._idx==0?1:0)).peephole());
+                    setDef(1,con( prj._idx==0 ? 1 : 0 ));
                     return this;
                 }
         return null;
diff --git a/src/main/java/com/seaofnodes/simple/node/LoadNode.java b/src/main/java/com/seaofnodes/simple/node/LoadNode.java
index eee5169d..6c74042b 100644
--- a/src/main/java/com/seaofnodes/simple/node/LoadNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/LoadNode.java
@@ -47,31 +47,38 @@ public class LoadNode extends MemOpNode {
     @Override
     public Node idealize() {
         Node ptr = ptr();
+        Node mem = mem();
 
         // Simple Load-after-Store on same address.
-        if( mem() instanceof StoreNode st &&
+        if( mem instanceof StoreNode st &&
             ptr == st.ptr() && off() == st.off() ) { // Must check same object
             assert _name.equals(st._name); // Equiv class aliasing is perfect
-            return st.val();
+            return extend(st.val());
         }
 
         // Simple Load-after-New on same address.
-        if( mem() instanceof ProjNode p && p.in(0) instanceof NewNode nnn &&
+        if( mem instanceof ProjNode p && p.in(0) instanceof NewNode nnn &&
             ptr == nnn.proj(1) ) // Must check same object
-            return nnn.in(nnn.findAlias(_alias)); // Load from New init
+            return zero(nnn);   // Load zero from new
+
+        // Uplift control to a prior dominating load.
+        for( Node memuse : mem._outputs )
+            // Find a prior load, has same mem,ptr,off but higher ctrl
+            if( memuse != this && memuse instanceof LoadNode ld && ptr==ld.ptr() && off()==ld.off() &&
+                cfg0()!=null && cfg0()._idom(ld.cfg0(),this) == ld.cfg0() ) // Higher control means load is legal earlier
+                return ld;
 
         // Load-after-Store on same address, but bypassing provably unrelated
         // stores.  This is a more complex superset of the above two peeps.
         // "Provably unrelated" is really weak.
         if( ptr instanceof ReadOnlyNode ro )
             ptr = ro.in(1);
-        Node mem = mem();
         outer:
         while( true ) {
             switch( mem ) {
             case StoreNode st:
                 if( ptr == st.ptr().addDep(this) && off() == st.off() )
-                    return castRO(st.val()); // Proved equal
+                    return extend(castRO(st.val())); // Proved equal
                 // Can we prove unequal?  Offsets do not overlap?
                 if( !off()._type.join(st.off()._type).isHigh() && // Offsets overlap
                     !neverAlias(ptr,st.ptr()) )                   // And might alias
@@ -88,10 +95,10 @@ public class LoadNode extends MemOpNode {
                 switch( mproj.in(0) ) {
                 case NewNode nnn1:
                     if( ptr instanceof ProjNode pproj && pproj.in(0) == mproj.in(0) )
-                        return castRO(nnn1.in(nnn1.findAlias(_alias))); // Load from New init
-                    if( !(ptr instanceof ProjNode pproj && pproj.in(0) instanceof NewNode nnn2) )
+                        return zero(nnn1);
+                    if( !(ptr instanceof ProjNode pproj && pproj.in(0) instanceof NewNode) )
                         break outer; // Cannot tell, ptr not related to New
-                    mem = nnn1.in(_alias);// Bypass unrelated New
+                    mem = nnn1.in(nnn1.findAlias(_alias));// Bypass unrelated New
                     break;
                 case StartNode  start: break outer;
                 case CallEndNode cend: break outer; // TODO: Bypass no-alias call
@@ -131,6 +138,13 @@ public class LoadNode extends MemOpNode {
         return null;
     }
 
+    // Load a flavored zero from a New
+    private Node zero(NewNode nnn) {
+        TypeStruct ts = nnn._ptr._obj;
+        Type zero = ts._fields[ts.findAlias(_alias)]._type.makeZero();
+        return castRO(new ConstantNode(zero).peephole());
+    }
+
     private Node ld( int idx ) {
         Node mem = mem(), ptr = ptr();
         return new LoadNode(_loc,_name,_alias,_declaredType,mem.in(idx),ptr instanceof PhiNode && ptr.in(0)==mem.in(0) ? ptr.in(idx) : ptr, off()).peephole();
@@ -178,4 +192,19 @@ public class LoadNode extends MemOpNode {
             return new ReadOnlyNode(rez).peephole();
         return rez;
     }
+
+    // When a load bypasses a store, the store might truncate bits - and the
+    // load will need to zero/sign-extend.
+    private Node extend(Node val) {
+        if( !(_declaredType instanceof TypeInteger ti) ) return val;
+        if( ti._min==0 )        // Unsigned
+            return new AndNode(null,val,con(ti._max));
+        // Signed extension
+        int shift = Long.numberOfLeadingZeros(ti._max)-1;
+        Node shf = con(shift);
+        if( shf._type==TypeInteger.ZERO )
+            return val;
+        //return peep(new SarNode(null,peep(new ShlNode(null,val,shf.keep())),shf.unkeep()));
+        throw Utils.TODO();
+    }
 }
diff --git a/src/main/java/com/seaofnodes/simple/node/LoopNode.java b/src/main/java/com/seaofnodes/simple/node/LoopNode.java
index f70a1012..d2b0e36c 100644
--- a/src/main/java/com/seaofnodes/simple/node/LoopNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/LoopNode.java
@@ -10,6 +10,7 @@ import java.util.HashSet;
 
 public class LoopNode extends RegionNode {
     public LoopNode( Parser.Lexer loc, Node entry ) { super(loc,null,entry,null); }
+    public LoopNode( LoopNode loop ) { super(loop); }
 
     public CFGNode entry() { return cfg(1); }
     public CFGNode back () { return cfg(2); }
diff --git a/src/main/java/com/seaofnodes/simple/node/MachConcreteNode.java b/src/main/java/com/seaofnodes/simple/node/MachConcreteNode.java
new file mode 100644
index 00000000..0c49fc64
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/MachConcreteNode.java
@@ -0,0 +1,27 @@
+package com.seaofnodes.simple.node;
+
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.Utils;
+import java.io.ByteArrayOutputStream;
+import java.util.BitSet;
+
+// Generic machine-specific class, has a few Node implementations that have to
+// exist (abstract) but are not useful past the optimizer.
+public abstract class MachConcreteNode extends Node implements MachNode{
+
+    public MachConcreteNode(Node node) { super(node); }
+    public MachConcreteNode(Node[]nodes) { super(nodes); }
+
+    @Override public String label() { return op(); }
+    @Override public Type compute () { throw Utils.TODO(); }
+    @Override public Node idealize() { throw Utils.TODO(); }
+
+    @Override public StringBuilder _print1(StringBuilder sb, BitSet visited) {
+        sb.append("(").append(op()).append(",");
+        for( int i=1; i<nIns(); i++ )
+            (in(i)==null ? sb.append(" ---") :  in(i)._print0(sb, visited)).append(",");
+        sb.setLength(sb.length()-1);
+        return sb.append(")");
+    }
+
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/MachNode.java b/src/main/java/com/seaofnodes/simple/node/MachNode.java
new file mode 100644
index 00000000..9f2fee85
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/MachNode.java
@@ -0,0 +1,49 @@
+package com.seaofnodes.simple.node;
+
+import com.seaofnodes.simple.*;
+import java.io.ByteArrayOutputStream;
+
+public interface MachNode {
+
+    // Easy access to the abstract Machine
+    default Machine machine() { return CodeGen.CODE._mach; }
+
+    // Run a post-instruction-selection action
+    default void postSelect() { }
+
+    // Register mask allowed on input i.  0 for no register.
+    abstract public RegMask regmap(int i);
+    // Register mask allowed as a result.  0 for no register.
+    abstract public RegMask outregmap();
+    // Multi-reg-defining machine op; idx comes from Proj.
+    // Sometimes these Projs have no uses, and just exist to kill a register.
+    default RegMask outregmap(int idx) { throw Utils.TODO(); }
+
+    // If this op updates the same register as input 'idx', e.g. many X86 "R1 +=
+    // R2" style ops.  This forces the output live range to equal the input live
+    // range, so they both get the same register.
+
+    // This can hold true for projections, if the instruction updates many
+    // registers that it also takes in.  Note that ops also use the same
+    // registers for both inputs and outputs but these are pinned and without any
+    // choices (e.g. always RCX for both an input and output) and are better
+    // served with just declaring as a fixed register.
+
+    // Returns either 0 for not-two-adr or the updated input; for projections
+    // this is their Multi's updated input.
+    default int twoAddress( ) { return 0; }
+
+    // Instructions cheaper to recreate than to spill, such as loading small constants
+    default boolean isClone() { return false; }
+    // Encoding is appended into the byte array; size is returned
+    abstract public int encoding(ByteArrayOutputStream bytes);
+
+    // Human-readable form appended to the SB.  Things like the encoding,
+    // indentation, leading address or block labels not printed here.
+    // Just something like "R17=[R18+12] // Load array base".
+    // General form: "dst=src+src".
+    default void asm(CodeGen code, SB sb) { throw Utils.TODO(); }
+
+    // Human readable opcode; e.g. "ld4" or "call".
+    default String op() { throw Utils.TODO(); }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java b/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
index 8a08853c..5363bb6f 100644
--- a/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
@@ -1,11 +1,8 @@
 package com.seaofnodes.simple.node;
 
-import com.seaofnodes.simple.IterPeeps;
-import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.Var;
+import com.seaofnodes.simple.*;
 import com.seaofnodes.simple.type.*;
 import java.util.*;
-import static com.seaofnodes.simple.Utils.TODO;
 
 /**
  *  Memory Merge - a merge of many aliases into a "fat memory".  All aliases
@@ -21,6 +18,7 @@ public class MemMergeNode extends Node {
     public final boolean _inProgress;
 
     public MemMergeNode( boolean inProgress) { _type = TypeMem.BOT; _inProgress = inProgress; }
+    public MemMergeNode(MemMergeNode mem) { super(mem); _inProgress = false; }
 
 
     // If being used by a Scope, this is "in progress" from the Parser.
@@ -139,7 +137,7 @@ public class MemMergeNode extends Node {
             if( in(i) instanceof PhiNode phi ) {
                 // Do an eager useless-phi removal
                 Node in = phi.peephole();
-                IterPeeps.addAll(phi._outputs);
+                CodeGen.CODE.addAll(phi._outputs);
                 phi.moveDepsToWorklist();
                 if( in != phi ) {
                     if( !phi.iskeep() ) // Keeping phi around for parser elsewhere
diff --git a/src/main/java/com/seaofnodes/simple/node/MemOpNode.java b/src/main/java/com/seaofnodes/simple/node/MemOpNode.java
index f9df2a40..d9ab6b89 100644
--- a/src/main/java/com/seaofnodes/simple/node/MemOpNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/MemOpNode.java
@@ -4,6 +4,8 @@ import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.Utils;
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeMemPtr;
+import java.lang.StringBuilder;
+import java.util.BitSet;
 
 /**
  * Convenience common base for Load and Store.
@@ -29,6 +31,13 @@ public abstract class MemOpNode extends Node {
         this(loc,name, alias, glb, mem, ptr, off);
         addDef(value);
     }
+    public MemOpNode( Node mach, MemOpNode mop ) {
+        super(mach);
+        _name  = mop._name;
+        _alias = mop._alias;
+        _declaredType = mop._declaredType;
+        _loc = mop._loc;
+    }
 
     //
     static String mlabel(String name) { return name.equals("[]") ? "ary" : (name.equals("#") ? "len" : name); }
@@ -38,6 +47,10 @@ public abstract class MemOpNode extends Node {
     public Node ptr() { return in(2); }
     public Node off() { return in(3); }
 
+    @Override StringBuilder _print1( StringBuilder sb, BitSet visited ) { return _printMach(sb,visited);  }
+    public StringBuilder _printMach( StringBuilder sb, BitSet visited ) { throw Utils.TODO(); }
+
+
     @Override
     boolean eq(Node n) {
         MemOpNode mem = (MemOpNode)n; // Invariant
diff --git a/src/main/java/com/seaofnodes/simple/node/MulNode.java b/src/main/java/com/seaofnodes/simple/node/MulNode.java
index b5ef91e9..4fdf987d 100644
--- a/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -1,8 +1,8 @@
 package com.seaofnodes.simple.node;
 
+import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeInteger;
-
 import java.util.BitSet;
 
 public class MulNode extends Node {
@@ -41,15 +41,33 @@ public class MulNode extends Node {
         Type t1 = lhs._type;
         Type t2 = rhs._type;
 
-        // Mul of 1.  We do not check for (1*x) because this will already
-        // canonicalize to (x*1)
-        if ( t2.isConstant() && t2 instanceof TypeInteger i && i.value()==1 )
-            return lhs;
-
         // Move constants to RHS: con*arg becomes arg*con
         if ( t1.isConstant() && !t2.isConstant() )
             return swap12();
 
+        // Multiply by constant
+        if ( t2.isConstant() && t2 instanceof TypeInteger i ) {
+            // Mul of 1.  We do not check for (1*x) because this will already
+            // canonicalize to (x*1)
+            long c = i.value();
+            if( c==1 )  return lhs;
+            if( c==0 )  return Parser.ZERO;
+            // Mul by a power of 2, +/-1.  Bit patterns more complex than this
+            // are unlikely to win on an X86 vs the normal "imul", and so
+            // become machine-specific.
+            if( (c & (c-1)) == 0 )
+                return new ShlNode(null,lhs,con(Long.numberOfTrailingZeros(c)));
+            // 2**n + 1, e.g. 9
+            long d = c-1;
+            if( (d & (d-1)) == 0 )
+                return new AddNode(new ShlNode(null,lhs,con(Long.numberOfTrailingZeros(d))).peephole(),lhs);
+            // 2**n - 1, e.g. 31
+            long e = c+1;
+            if( (e & (e-1)) == 0 )
+                return new SubNode(new ShlNode(null,lhs,con(Long.numberOfTrailingZeros(e))).peephole(),lhs);
+
+        }
+
         // Do we have ((x * (phi cons)) * con) ?
         // Do we have ((x * (phi cons)) * (phi cons)) ?
         // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
diff --git a/src/main/java/com/seaofnodes/simple/node/MultiUse.java b/src/main/java/com/seaofnodes/simple/node/MultiUse.java
deleted file mode 100644
index 436d3432..00000000
--- a/src/main/java/com/seaofnodes/simple/node/MultiUse.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package com.seaofnodes.simple.node;
-
-public interface MultiUse {
-    abstract int idx();
-}
diff --git a/src/main/java/com/seaofnodes/simple/node/NewNode.java b/src/main/java/com/seaofnodes/simple/node/NewNode.java
index 34d695f4..80545d66 100644
--- a/src/main/java/com/seaofnodes/simple/node/NewNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/NewNode.java
@@ -24,17 +24,16 @@ public class NewNode extends Node implements MultiNode {
         assert nodes[0]._type==Type.CONTROL || nodes[0]._type == Type.XCONTROL;
         // Malloc-length in slot 1
         assert nodes[1]._type instanceof TypeInteger || nodes[1]._type==Type.NIL;
-        for( int i=0; i<_len; i++ ) {
+        for( int i=0; i<_len; i++ )
             // Memory slices for all fields.
-            assert nodes[2+         i]._type.isa(TypeMem.BOT);
-            // Value  slices for all fields.
-            assert nodes[2 + _len + i]._type != null;
-        }
+            assert nodes[2+i]._type.isa(TypeMem.BOT);
     }
 
-    @Override public String label() {
-        return "new_"+glabel();
-    }
+    public NewNode(NewNode nnn) { super(nnn); _ptr = nnn._ptr; _len = nnn._len; }
+
+    public Node mem (int idx) { return in(idx+2); }
+
+    @Override public String label() { return "new_"+glabel(); }
     @Override public String glabel() {
         return _ptr._obj.isAry() ? "ary_"+_ptr._obj._fields[1]._type.str() : _ptr._obj.str();
     }
@@ -45,11 +44,17 @@ public class NewNode extends Node implements MultiNode {
         return sb.append(_ptr._obj.str());
     }
 
-    // Find matching alias input
     int findAlias(int alias) {
-        return 2+_ptr._obj.findAlias(alias)+_len;
+        int idx = _ptr._obj.findAlias(alias);
+        assert idx!= -1;        // Error, caller should be calling
+        return idx+2;           // Skip ctrl, size
     }
 
+    // 0 - ctrl
+    // 1 - byte size
+    // 2-len+2 - aliases, one per field
+    // len+2 - 2*len+2 - initial values, one per field
+    public Node size() { return in(1); }
 
     @Override
     public TypeTuple compute() {
@@ -60,8 +65,9 @@ public class NewNode extends Node implements MultiNode {
         for( int i=0; i<fs.length; i++ ) {
             Type mt = in(i+2)._type;
             TypeMem mem = mt==Type.TOP ? TypeMem.TOP : (TypeMem)mt;
-            Type tfld = in(2+_len+i)._type.meet(mem._t);
-            ts[i+2] = TypeMem.make(fs[i]._alias,tfld);
+            Type tfld = mem._t.meet(mem._t.makeZero());
+            Type tfld2 = tfld.join(fs[i]._type);
+            ts[i+2] = TypeMem.make(fs[i]._alias,tfld2);
         }
         return TypeTuple.make(ts);
     }
diff --git a/src/main/java/com/seaofnodes/simple/node/Node.java b/src/main/java/com/seaofnodes/simple/node/Node.java
index 4c6cce16..bbf1ebe9 100644
--- a/src/main/java/com/seaofnodes/simple/node/Node.java
+++ b/src/main/java/com/seaofnodes/simple/node/Node.java
@@ -3,8 +3,10 @@ package com.seaofnodes.simple.node;
 import com.seaofnodes.simple.*;
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeFloat;
+import com.seaofnodes.simple.type.TypeInteger;
 import java.util.*;
 import java.util.function.Function;
+import static com.seaofnodes.simple.CodeGen.CODE;
 
 /**
  * All Nodes in the Sea of Nodes IR inherit from the Node class.
@@ -48,16 +50,8 @@ public abstract class Node {
     public Type _type;
 
 
-    /**
-     * A private Global Static mutable counter, for unique node id generation.
-     * To make the compiler multithreaded, this field will have to move into a TLS.
-     * Starting with value 1, to avoid bugs confusing node ID 0 with uninitialized values.
-     * */
-    private static int UNIQUE_ID = 1;
-    public static int UID() { return UNIQUE_ID; }
-
-    protected Node(Node... inputs) {
-        _nid = UNIQUE_ID++; // allocate unique dense ID
+    Node(Node... inputs) {
+        _nid = CODE.getUID(); // allocate unique dense ID
         _inputs = new Ary<>(Node.class);
         Collections.addAll(_inputs,inputs);
         _outputs = new Ary<>(Node.class);
@@ -66,6 +60,18 @@ public abstract class Node {
                 n.addUse( this );
     }
 
+    // Make a Node using the existing arrays of nodes.
+    // Used by any pass rewriting all Node classes but not the edges.
+    Node( Node n ) {
+        assert CodeGen.CODE._phase == CodeGen.Phase.InstructionSelection;
+        _nid = CODE.getUID(); // allocate unique dense ID
+        _inputs  = new Ary<>(n._inputs.asAry());
+        _outputs = new Ary<>(Node.class);
+        _type = n._type;
+        _deps = null;
+        _hash = 0;
+    }
+
     // Easy reading label for debugger, e.g. "Add" or "Region" or "EQ"
     public abstract String label();
 
@@ -79,6 +85,9 @@ public abstract class Node {
     // Graphical label, e.g. "+" or "Region" or "=="
     public String glabel() { return label(); }
 
+    // Extra fun stuff, for assembly printing.  Jump labels, parser locations,
+    // variable types, etc.
+    public String comment() { return null; }
 
     // ------------------------------------------------------------------------
 
@@ -163,10 +172,10 @@ public abstract class Node {
             new_def.addUse(this);
         // Set the new_def over the old (killed) edge
         _inputs.set(idx,new_def);
-        if( old_def != null ) {          // If the old def exists, remove a def->use edge
-            if( old_def.delUse(this) )  // If we removed the last use, the old def is now dead
-                old_def.kill();         // Kill old def
-            else IterPeeps.add(old_def);// Else old lost a use, so onto worklist
+        if( old_def != null ) {        // If the old def exists, remove a def->use edge
+            if( old_def.delUse(this) ) // If we removed the last use, the old def is now dead
+                old_def.kill();        // Kill old def
+            else CODE.add(old_def);    // Else old lost a use, so onto worklist
         }
         moveDepsToWorklist();
         // Return new_def for easy flow-coding
@@ -246,11 +255,9 @@ public abstract class Node {
         _type=null;             // Flag as dead
         while( nIns()>0 ) { // Set all inputs to null, recursively killing unused Nodes
             Node old_def = _inputs.removeLast();
-            if( old_def != null ) {
-                IterPeeps.add(old_def);// Revisit neighbor because removed use
-                if( old_def.delUse(this) ) // If we removed the last use, the old def is now dead
-                    old_def.kill();        // Kill old def
-            }
+            // Revisit neighbor because removed use
+            if( old_def != null && CODE.add(old_def).delUse(this) )
+                old_def.kill(); // If we removed the last use, the old def is now dead
         }
         assert isDead();        // Really dead now
     }
@@ -283,7 +290,7 @@ public abstract class Node {
             int idx = n._inputs.find(this);
             n._inputs.set(idx,nnn);
             nnn.addUse(n);
-            IterPeeps.addAll(n._outputs);
+            CODE.addAll(n._outputs);
         }
         kill();
     }
@@ -291,12 +298,6 @@ public abstract class Node {
     // ------------------------------------------------------------------------
     // Graph-based optimizations
 
-    /**
-     * We allow disabling peephole opt so that we can observe the
-     * full graph, vs the optimized graph.
-     */
-    public static boolean _disablePeephole = false;
-
     /**
      * Try to peephole at this node and return a better replacement Node.
      * Always returns some not-null Node (often this).
@@ -329,28 +330,22 @@ public abstract class Node {
      * </ul>
      */
     public final Node peepholeOpt( ) {
-        ITER_CNT++;
+        CODE.iterCnt();
         // Compute initial or improved Type
         Type old = setType(compute());
 
-        // Peepholes can be turned off - except for cleaning up dead CFG paths.
-        // These need to clean up so the following code motion algorithms don't
-        // get confused by dead or infinite paths.
-        if( _disablePeephole && !(this instanceof RegionNode) && !(this instanceof PhiNode) )
-            return old==_type ? null : this;   // Peephole optimizations turned off
-
         // Replace constant computations from non-constants with a constant
         // node.  If peeps are disabled, still allow high Phis to collapse;
         // they typically come from dead Regions, and we want the Region to
         // collapse, which requires the Phis to die first.
-        if( _type.isHighOrConst() && !isConst() && (!_disablePeephole || _type.isHigh()) )
-            return ConstantNode.make(_type).peepholeOpt();
+        if( _type.isHighOrConst() && !isConst() )
+            return ConstantNode.make(_type).peephole();
 
         // Global Value Numbering
         if( _hash==0 ) {
-            Node n = GVN.get(this); // Will set _hash as a side effect
+            Node n = CODE._gvn.get(this); // Will set _hash as a side effect
             if( n==null )
-                GVN.put(this,this);  // Put in table now
+                CODE._gvn.put(this,this);  // Put in table now
             else {
                 // Because of random worklist ordering, the two equal nodes
                 // might have different types.  Because of monotonicity, both
@@ -368,10 +363,9 @@ public abstract class Node {
             return n;           // Report progress
 
         if( old!=_type ) return this; // Report progress;
-        ITER_NOP_CNT++;
+        CODE.iterNop();
         return null;            // No progress
     }
-    public static int ITER_CNT, ITER_NOP_CNT;
 
     // m is the new Node, self is the old.
     // Return 'm', which may have zero uses but is alive nonetheless.
@@ -415,7 +409,7 @@ public abstract class Node {
         assert old==null || type.isa(old); // Since _type not set, can just re-run this in assert in the debugger
         if( old == type ) return old;
         _type = type;       // Set _type late for easier assert debugging
-        IterPeeps.addAll(_outputs);
+        CODE.addAll(_outputs);
         moveDepsToWorklist();
         return old;
     }
@@ -485,7 +479,8 @@ public abstract class Node {
     Node addDep( Node dep ) {
         // Running peepholes during the big assert cannot have side effects
         // like adding dependencies.
-        if( IterPeeps.midAssert() ) return this;
+        if( CODE._midAssert ) return this;
+        if( dep == null ) return this;
         if( _deps==null ) _deps = new Ary<>(Node.class);
         if( _deps   .find(dep) != -1 ) return this; // Already on list
         if( _inputs .find(dep) != -1 ) return this; // No need for deps on immediate neighbors
@@ -497,15 +492,11 @@ public abstract class Node {
     // Move the dependents onto a worklist, and clear for future dependents.
     public void moveDepsToWorklist( ) {
         if( _deps==null ) return;
-        IterPeeps.addAll(_deps);
+        CODE.addAll(_deps);
         _deps.clear();
     }
 
 
-    // Global Value Numbering.  Hash over opcode and inputs; hits in this table
-    // are structurally equal.
-    public static final HashMap<Node,Node> GVN = new HashMap<>();
-
     // Two nodes are equal if they have the same inputs and the same "opcode"
     // which means the same Java class, plus same internal parts.
     @Override public final boolean equals( Object o ) {
@@ -534,7 +525,7 @@ public abstract class Node {
     // If the _hash is set, then the Node is in the GVN table; remove it.
     void unlock() {
         if( _hash==0 ) return;
-        Node old = GVN.remove(this); // Pull from table
+        Node old = CODE._gvn.remove(this); // Pull from table
         assert old==this;
         _hash=0;                // Out of table now
     }
@@ -618,31 +609,21 @@ public abstract class Node {
     // Report any post-optimize errors
     public Parser.ParseException err() { return null; }
 
-    /**
-     * Used to allow repeating tests in the same JVM.  This just resets the
-     * Node unique id generator, and is done as part of making a new Parser.
-     */
-    public static void reset() {
-        UNIQUE_ID = 1;
-        _disablePeephole=false;
-        GVN.clear();
-        ITER_CNT = ITER_NOP_CNT = 0;
-    }
-
+    // Common integer constants
+    public static ConstantNode con(long x) { return (ConstantNode)(new ConstantNode(TypeInteger.constant(x)).peephole()); }
 
     // Utility to walk the entire graph applying a function; return the first
     // not-null result.
-    private static final BitSet WVISIT = new BitSet();
     final public <E> E walk( Function<Node,E> pred ) {
-        assert WVISIT.isEmpty();
+        assert CODE._visit.isEmpty();
         E rez = _walk(pred);
-        WVISIT.clear();
+        CODE._visit.clear();
         return rez;
     }
 
     private <E> E _walk( Function<Node,E> pred ) {
-        if( WVISIT.get(_nid) ) return null; // Been there, done that
-        WVISIT.set(_nid);
+        if( CODE._visit.get(_nid) ) return null; // Been there, done that
+        CODE._visit.set(_nid);
         E x = pred.apply(this);
         if( x != null ) return x;
         for( Node def : _inputs  )  if( def != null && (x = def._walk(pred)) != null ) return x;
diff --git a/src/main/java/com/seaofnodes/simple/node/ParmNode.java b/src/main/java/com/seaofnodes/simple/node/ParmNode.java
index 784b9146..8d7c4205 100644
--- a/src/main/java/com/seaofnodes/simple/node/ParmNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ParmNode.java
@@ -13,6 +13,7 @@ public class ParmNode extends PhiNode {
         super(label,declaredType,inputs);
         _idx = idx;
     }
+    public ParmNode(ParmNode parm) { super(parm, parm._label, parm._declaredType); _idx = parm._idx; }
 
     @Override public String label() { return MemOpNode.mlabel(_label); }
 
@@ -22,7 +23,7 @@ public class ParmNode extends PhiNode {
 
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        if( "main".equals(fun().sig()._name) && _label.equals("arg") )
+        if( "main".equals(fun()._name) && _label.equals("arg") )
             return sb.append("arg");
         sb.append("Parm_").append(_label).append("(");
         for( Node in : _inputs ) {
diff --git a/src/main/java/com/seaofnodes/simple/node/PhiNode.java b/src/main/java/com/seaofnodes/simple/node/PhiNode.java
index 9aed8287..17748afe 100644
--- a/src/main/java/com/seaofnodes/simple/node/PhiNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/PhiNode.java
@@ -13,9 +13,11 @@ public class PhiNode extends Node {
     final Type _declaredType;
 
     public PhiNode(String label, Type declaredType, Node... inputs) { super(inputs); _label = label;  assert declaredType!=null; _declaredType = declaredType; }
+    public PhiNode(PhiNode phi, String label, Type declaredType) { super(phi); _label = label; _declaredType = declaredType; }
+    public PhiNode(PhiNode phi) { super(phi); _label = phi._label; _declaredType = phi._declaredType;  }
 
     public PhiNode(RegionNode r, Node sample) {
-        super(r);
+        super(new Node[]{r});
         _label = "";
         _declaredType = sample._type;
         while( nIns() < r.nIns() )
@@ -73,9 +75,6 @@ public class PhiNode extends Node {
         Node live = singleUniqueInput();
         if (live != null)
             return live;
-        // No more fancy peeps
-        if( _disablePeephole )
-            return null;
 
         // No bother if region is going to fold dead paths soon
         for( int i=1; i<nIns(); i++ )
diff --git a/src/main/java/com/seaofnodes/simple/node/ProjNode.java b/src/main/java/com/seaofnodes/simple/node/ProjNode.java
index ea211dd2..ef7b17e4 100644
--- a/src/main/java/com/seaofnodes/simple/node/ProjNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ProjNode.java
@@ -6,7 +6,7 @@ import com.seaofnodes.simple.type.TypeTuple;
 
 import java.util.BitSet;
 
-public class ProjNode extends Node implements MultiUse {
+public class ProjNode extends Node {
 
     // Which slice of the incoming multipart value
     public final int _idx;
@@ -15,13 +15,13 @@ public class ProjNode extends Node implements MultiUse {
     public final String _label;
 
     public ProjNode(Node ctrl, int idx, String label) {
-        super(ctrl);
+        super(new Node[]{ctrl});
         _idx = idx;
         _label = label;
     }
+    public ProjNode(ProjNode p) { super(p); _idx = p._idx; _label = p._label; }
 
     @Override public String label() { return _label; }
-    @Override public int idx() { return _idx; }
 
     @Override
     StringBuilder _print1(StringBuilder sb, BitSet visited) {
diff --git a/src/main/java/com/seaofnodes/simple/node/ReadOnlyNode.java b/src/main/java/com/seaofnodes/simple/node/ReadOnlyNode.java
index fddcaa67..b755af3f 100644
--- a/src/main/java/com/seaofnodes/simple/node/ReadOnlyNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ReadOnlyNode.java
@@ -10,6 +10,7 @@ import java.util.BitSet;
  */
 public class ReadOnlyNode extends Node {
     public ReadOnlyNode( Node n ) { super(null,n); }
+    public ReadOnlyNode( ReadOnlyNode n ) { super(n); }
     @Override public String label() { return "ReadOnly"; }
 
     @Override
diff --git a/src/main/java/com/seaofnodes/simple/node/RegionNode.java b/src/main/java/com/seaofnodes/simple/node/RegionNode.java
index ea053c02..5d3db5c6 100644
--- a/src/main/java/com/seaofnodes/simple/node/RegionNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/RegionNode.java
@@ -1,20 +1,16 @@
 package com.seaofnodes.simple.node;
 
-import com.seaofnodes.simple.IterPeeps;
-import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.Utils;
+import com.seaofnodes.simple.*;
 import com.seaofnodes.simple.type.Type;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.BitSet;
-import java.util.HashSet;
+import java.util.*;
 
 public class RegionNode extends CFGNode {
     // Source location for late discovered errors
     public Parser.Lexer _loc;
 
-    public RegionNode(Node... nodes) { this(null,nodes); }
-    public RegionNode(Parser.Lexer loc, Node... nodes) { super(nodes); _loc = loc; }
+    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); _loc = r._loc; }
 
     @Override
     public String label() { return "Region"; }
@@ -39,37 +35,16 @@ public class RegionNode extends CFGNode {
     @Override
     public Node idealize() {
         if( inProgress() ) return null;
-        // Delete dead paths into a Region
-        int path = findDeadInput();
-        if( path != 0 &&
-            // Do not delete the entry path of a loop (ok to remove the back
-            // edge and make the loop a single-entry Region which folds away
-            // the Loop).  Folding the entry path confused the loop structure,
-            // moving the backedge to the entry point.
-            !(this instanceof LoopNode loop && loop.entry()==in(path)) ) {
-            // Cannot use the obvious output iterator here, because a Phi
-            // deleting an input might recursively delete *itself*.  This
-            // shuffles the output array, and we might miss iterating an
-            // unrelated Phi. So on rare occasions we repeat the loop to get
-            // all the Phis.
-            int nouts = 0;
-            while( nouts != nOuts() ) {
-                nouts = nOuts();
-                for( int i=0; i<nOuts(); i++ )
-                    if( out(i) instanceof PhiNode phi && phi.nIns()==nIns() ) {
-                        phi.delDef(path);
-                        IterPeeps.addAll(phi._outputs);
-                    }
-            }
-            return isDead() ? Parser.XCTRL : delDef(path);
-        }
+
+        Node progress = deadPath();
+        if( progress!=null ) return progress;
+
         // If down to a single input, become that input
         if( nIns()==2 && !hasPhi() )
             return in(1);       // Collapse if no Phis; 1-input Phis will collapse on their own
 
         // If a CFG diamond with no merging, delete: "if( pred ) {} else {};"
-        if( !_disablePeephole && // Optional
-            !hasPhi() &&         // No Phi users, just a control user
+        if( !hasPhi() &&         // No Phi users, just a control user
             in(1) instanceof CProjNode p1 &&
             in(2) instanceof CProjNode p2 &&
             p1.in(0).addDep(this)==p2.in(0).addDep(this) &&
@@ -84,6 +59,31 @@ public class RegionNode extends CFGNode {
         return null;
     }
 
+    Node deadPath() {
+        // Delete dead paths into a Region
+        int path = findDeadInput();
+        if( path==0 ) return null;
+        // Do not delete the entry path of a loop (ok to remove the back edge
+        // and make the loop a single-entry Region which folds away the Loop).
+        // Folding the entry path confused the loop structure, moving the
+        // backedge to the entry point.
+        if( this instanceof LoopNode loop && loop.entry()==in(path) )
+            return null;
+        // Cannot use the obvious output iterator here, because a Phi deleting
+        // an input might recursively delete *itself*.  This shuffles the
+        // output array, and we might miss iterating an unrelated Phi. So on
+        // rare occasions we repeat the loop to get all the Phis.
+        int nouts = 0;
+        while( nouts != nOuts() ) {
+            nouts = nOuts();
+            for( int i=0; i<nOuts(); i++ )
+                if( out(i) instanceof PhiNode phi && phi.nIns()==nIns() )
+                    CodeGen.CODE.addAll(phi.delDef(path)._outputs);
+        }
+        return isDead() ? Parser.XCTRL : delDef(path);
+    }
+
+
     private int findDeadInput() {
         for( int i=1; i<nIns(); i++ )
             if( in(i)._type==Type.XCONTROL )
diff --git a/src/main/java/com/seaofnodes/simple/node/ReturnNode.java b/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
index e543f9ea..20b6c7b9 100644
--- a/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ReturnNode.java
@@ -17,12 +17,13 @@ import java.util.BitSet;
  */
 public class ReturnNode extends CFGNode {
 
-    public final FunNode _fun;
+    public FunNode _fun;
 
     public ReturnNode(Node ctrl, Node mem, Node data, Node rpc, FunNode fun ) {
         super(ctrl, mem, data, rpc);
         _fun = fun;
     }
+    public ReturnNode( ReturnNode ret, FunNode fun ) { super(ret);  _fun = fun;  }
 
     public Node ctrl() { return in(0); }
     public Node mem () { return in(1); }
@@ -113,7 +114,7 @@ public class ReturnNode extends CFGNode {
     }
 
     @Override public Parser.ParseException err() {
-        return mt==Type.BOTTOM ? mixerr(ti,tf,tp,tn,_fun._loc) : null;
+        return expr()._type/*mt*/==Type.BOTTOM ? mixerr(ti,tf,tp,tn,_fun._loc) : null;
     }
 
     static Parser.ParseException mixerr( boolean ti, boolean tf, boolean tp, boolean tn, Parser.Lexer loc ) {
diff --git a/src/main/java/com/seaofnodes/simple/node/ScopeNode.java b/src/main/java/com/seaofnodes/simple/node/ScopeNode.java
index d0d86b79..1208ff63 100644
--- a/src/main/java/com/seaofnodes/simple/node/ScopeNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/ScopeNode.java
@@ -276,7 +276,7 @@ public class ScopeNode extends MemMergeNode {
         mem()._merge(that.mem(),r);
         this ._merge(that      ,r);
         that.kill();            // Kill merged scope
-        IterPeeps.add(r);
+        CodeGen.CODE.add(r);
         return r.unkeep();
     }
 
@@ -351,7 +351,7 @@ public class ScopeNode extends MemMergeNode {
             return;           // Dead, do not add any guards
         // Invert the If conditional
         if( invert )
-            pred = pred instanceof NotNode not ? not.in(1) : IterPeeps.add(new NotNode(pred).peephole());
+            pred = pred instanceof NotNode not ? not.in(1) : CodeGen.CODE.add(new NotNode(pred).peephole());
         // This is a zero/null test.
         // Compute the positive test type.
         Type tnz = pred._type.nonZero();
diff --git a/src/main/java/com/seaofnodes/simple/node/StartNode.java b/src/main/java/com/seaofnodes/simple/node/StartNode.java
index 50cba348..26e08535 100644
--- a/src/main/java/com/seaofnodes/simple/node/StartNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/StartNode.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple.node;
 
+import com.seaofnodes.simple.CodeGen;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.type.*;
 import java.util.Arrays;
@@ -18,7 +19,8 @@ public class StartNode extends LoopNode implements MultiNode {
 
     final Type _arg;
 
-    public StartNode(Type arg) { super(null,null); _arg = arg; _type = compute(); }
+    public StartNode(Type arg) { super((Parser.Lexer)null,null); _arg = arg; _type = compute(); }
+    public StartNode(StartNode start) { super(start); _arg = start._arg; }
 
     @Override public String label() { return "Start"; }
 
@@ -37,7 +39,7 @@ public class StartNode extends LoopNode implements MultiNode {
         // Find "main", its the start.
         CFGNode C = null;
         for( Node use : _outputs )
-            if( use instanceof FunNode fun && fun.sig().isa(TypeFunPtr.MAIN) )
+            if( use instanceof FunNode fun && fun.sig().isa(CodeGen.CODE._main) )
                 { assert C==null; C = fun; }
         return C;
     }
diff --git a/src/main/java/com/seaofnodes/simple/node/StopNode.java b/src/main/java/com/seaofnodes/simple/node/StopNode.java
index feb8347f..6aaba3b3 100644
--- a/src/main/java/com/seaofnodes/simple/node/StopNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/StopNode.java
@@ -13,6 +13,7 @@ public class StopNode extends CFGNode {
         _src = src;
         _type = compute();
     }
+    public StopNode(StopNode stop) { super(stop);  _src = stop._src; }
 
     @Override
     public String label() {
diff --git a/src/main/java/com/seaofnodes/simple/node/StoreNode.java b/src/main/java/com/seaofnodes/simple/node/StoreNode.java
index 0fa7d591..93294dba 100644
--- a/src/main/java/com/seaofnodes/simple/node/StoreNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/StoreNode.java
@@ -1,8 +1,6 @@
 package com.seaofnodes.simple.node;
 
-import com.seaofnodes.simple.IterPeeps;
-import com.seaofnodes.simple.Parser;
-import com.seaofnodes.simple.Utils;
+import com.seaofnodes.simple.*;
 import com.seaofnodes.simple.type.*;
 import java.util.BitSet;
 
@@ -73,33 +71,20 @@ public class StoreNode extends MemOpNode {
             return this;
         }
 
-        // Simple store-after-new on same address.  Should pick up
-        // an init-store being stomped by a first user store.
-        if( mem() instanceof ProjNode st  && st .in(0) instanceof NewNode nnn &&
-            ptr() instanceof ProjNode ptr && ptr.in(0) == nnn &&
-            ptr()._type instanceof TypeMemPtr tmp && // No bother if weird dead pointers
-            // Cannot fold a store of a single element over the array body initializer value
-            !(tmp._obj.isAry() && tmp._obj._fields[1]._alias==_alias) &&
-            // Very sad strong cutout: val has to be legal to hoist to a New
-            // input, which means it cannot depend on the New.  Many, many
-            // things are legal here but difficult to check without doing a
-            // full dominator check.  Example failure:
-            // "struct C { C? c; }; C self = new C { c=self; }"
-            val()._type.isHighOrConst() &&
-            // Must have exactly one use of "this" or you get weird
-            // non-serializable memory effects in the worse case.
-            checkOnlyUse(st) &&
-            // Folding away a broken store
-            err()==null ) {
-            nnn.setDef(nnn.findAlias(_alias),val());
-            // Must *retype* the NewNode, this is not monotonic in isolation
-            // but is monotonic counting from this Store to the New.
-            nnn  ._type = nnn  .compute();
-            mem()._type = mem().compute();
-            IterPeeps.addAll(nnn._outputs);
-            return mem();
+        // Value is automatically truncated by narrow store
+        if( val() instanceof AndNode and && and.in(2)._type.isConstant()  ) {
+            int log = _declaredType.log_size();
+            if( log<3 ) {       // And-mask vs narrow store
+                long mask = ((TypeInteger)and.in(2)._type).value();
+                long bits = (1L<<(8<<log))-1;
+                // Mask does not mask any of the stored bits
+                if( (bits&mask)==bits )
+                    // So and-mask is already covered by the store
+                    { setDef(4,and.in(1)); return this; }
+            }
         }
 
+
         return null;
     }
 
@@ -119,9 +104,10 @@ public class StoreNode extends MemOpNode {
         Parser.ParseException err = super.err();
         if( err != null ) return err;
         TypeMemPtr tmp = (TypeMemPtr)ptr()._type;
-        if( tmp._obj.field(_name)._final && !"[]".equals(_name) )
+        if( tmp._obj.field(_name)._final && !_init )
             return Parser.error("Cannot modify final field '"+_name+"'",_loc);
         Type t = val()._type;
-        return _init || t.isa(_declaredType) ? null : Parser.error("Cannot store "+t+" into field "+_declaredType+" "+_name,_loc);
+        //return _init || t.isa(_declaredType) ? null : Parser.error("Cannot store "+t+" into field "+_declaredType+" "+_name,_loc);
+        return null;
     }
 }
diff --git a/src/main/java/com/seaofnodes/simple/node/XCtrlNode.java b/src/main/java/com/seaofnodes/simple/node/XCtrlNode.java
index 3c6a5df3..9b4245c7 100644
--- a/src/main/java/com/seaofnodes/simple/node/XCtrlNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/XCtrlNode.java
@@ -1,11 +1,12 @@
 package com.seaofnodes.simple.node;
 
+import com.seaofnodes.simple.CodeGen;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.type.Type;
 import java.util.BitSet;
 
 public class XCtrlNode extends CFGNode {
-    public XCtrlNode() { super(Parser.START); }
+    public XCtrlNode() { super(new Node[]{CodeGen.CODE._start}); }
     @Override public String label() { return "Xctrl"; }
     @Override StringBuilder _print1(StringBuilder sb, BitSet visited) { return sb.append("Xctrl"); }
     @Override public boolean isConst() { return true; }
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFMemX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFMemX86.java
new file mode 100644
index 00000000..4f75edcd
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFMemX86.java
@@ -0,0 +1,33 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.CodeGen;
+import com.seaofnodes.simple.Utils;
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.node.*;
+
+public class AddFMemX86 extends MemOpX86 {
+    AddFMemX86( AddFNode add, LoadNode ld , Node base, Node idx, int off, int scale, Node val ) {
+        super(add,ld, base, idx, off, scale, 0, val );
+    }
+
+    @Override public RegMask regmap(int i) {
+        if( i==1 ) return RegMask.EMPTY;    // Memory
+        if( i==2 ) return x86_64_v2.RMASK;  // base
+        if( i==3 ) return x86_64_v2.RMASK;  // index
+        if( i==4 ) return x86_64_v2.XMASK;  // value
+        throw Utils.TODO();
+    }
+
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.XMASK; }
+
+
+    // General form: "add  dst = src + [base + idx<<2 + 12]"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ");
+        sb.p(val()==null ? "#"+_imm : code.reg(val())).p(" + ");
+        asm_address(code,sb);
+    }
+    @Override public String op() { return "addf"+_sz; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFX86.java
new file mode 100644
index 00000000..a3f5c7b3
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFX86.java
@@ -0,0 +1,29 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class AddFX86 extends MachConcreteNode implements MachNode {
+    AddFX86( Node addf ) { super(addf); }
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) { assert i==1 || i==2; return x86_64_v2.XMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.XMASK; }
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "addf  dst += src"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" + ").p(code.reg(in(2)));
+    }
+
+    @Override public String op() { return "addf"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddIX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddIX86.java
new file mode 100644
index 00000000..6a332ff5
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddIX86.java
@@ -0,0 +1,39 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class AddIX86 extends MachConcreteNode implements MachNode {
+    final TypeInteger _ti;
+    AddIX86( Node add, TypeInteger ti ) {
+        super(add);
+        _inputs.pop();
+         _ti = ti;
+    }
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) {
+        // assert i== i;
+        return x86_64_v2.WMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "addi  dst += #imm"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" + #");
+        _ti.print(sb);
+    }
+
+    @Override public String op() {
+        return _ti.value() == 1  ? "inc" : (_ti.value() == -1 ? "dec" : "addi");
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddMemX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddMemX86.java
new file mode 100644
index 00000000..7d45d757
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddMemX86.java
@@ -0,0 +1,25 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.CodeGen;
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.node.*;
+
+public class AddMemX86 extends MemOpX86 {
+    AddMemX86( AddNode add, LoadNode ld , Node base, Node idx, int off, int scale, int imm, Node val ) {
+        super(add,ld, base, idx, off, scale, imm, val );
+    }
+
+    @Override public String op() { return "add"+_sz; }
+
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+
+    // General form: "add  dst = src + [base + idx<<2 + 12]"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ");
+        sb.p(val()==null ? "#"+_imm : code.reg(val())).p(" + ");
+        asm_address(code,sb);
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddX86.java
new file mode 100644
index 00000000..61aa5a9e
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddX86.java
@@ -0,0 +1,29 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class AddX86 extends MachConcreteNode implements MachNode {
+    AddX86( Node add ) { super(add); }
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) { assert i==1 || i==2; return x86_64_v2.RMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "add  dst += src"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" + ").p(code.reg(in(2)));
+    }
+
+    @Override public String op() { return "add"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AndIX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AndIX86.java
new file mode 100644
index 00000000..f2ee1c66
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AndIX86.java
@@ -0,0 +1,42 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+import java.util.BitSet;
+import java.lang.StringBuilder;
+
+public class AndIX86 extends MachConcreteNode implements MachNode {
+    final TypeInteger _ti;
+    AndIX86(Node and, TypeInteger ti) {
+    super(and);
+    _inputs.pop();
+    _ti = ti;
+    }
+
+    // Register mask allowed on input i.
+    // This is the normal calling convention
+    @Override public RegMask regmap(int i) { assert i==1; return x86_64_v2.WMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form
+    // General form: "andi  dst & #imm"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" & #");
+        _ti.print(sb);
+    }
+
+    @Override public String op() { return "andi"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallRX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallRX86.java
new file mode 100644
index 00000000..31d303ed
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallRX86.java
@@ -0,0 +1,31 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.type.TypeFunPtr;
+import java.io.ByteArrayOutputStream;
+
+public class CallRX86 extends CallNode implements MachNode {
+    CallRX86( CallNode call ) { super(call); }
+
+    @Override public String label() { return op(); }
+    @Override public RegMask regmap(int i) {
+        return i==_inputs._len
+            ? x86_64_v2.WMASK          // Function call target
+            : x86_64_v2.callInMask(i); // Normal argument
+    }
+    @Override public RegMask outregmap() { return x86_64_v2.RET_MASK; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(fptr()));
+    }
+
+    @Override public String op() { return "callr"; }
+
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallX86.java
new file mode 100644
index 00000000..9c246c24
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallX86.java
@@ -0,0 +1,40 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.type.TypeFunPtr;
+import java.io.ByteArrayOutputStream;
+import java.util.BitSet;
+
+public class CallX86 extends CallNode implements MachNode {
+    final TypeFunPtr _tfp;
+    final String _name;
+    CallX86( CallNode call, TypeFunPtr tfp ) {
+        super(call);
+        _inputs.pop(); // Pop constant target
+        assert tfp.isConstant();
+        _tfp = tfp;
+        _name = CodeGen.CODE.link(tfp)._name;
+    }
+
+    @Override public String label() { return op(); }
+    @Override public RegMask regmap(int i) {
+        return x86_64_v2.callInMask(i); // Normal argument
+    }
+    @Override public RegMask outregmap() { return x86_64_v2.RET_MASK; }
+
+    @Override public String name() { return _name; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(_name);
+    }
+
+    @Override public String op() { return "call"; }
+
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpIX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpIX86.java
new file mode 100644
index 00000000..2fa7fbb1
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpIX86.java
@@ -0,0 +1,43 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+// Compare immediate.  Sets flags.
+public class CmpIX86 extends MachConcreteNode implements MachNode {
+    final int _imm;
+    final String _bop;
+    CmpIX86( BoolNode bool, TypeInteger ti ) {
+        super(bool);
+        _inputs.pop(); // Toss ideal ConstantNode away, embedded into machine op
+        _bop = bool.op();       // One of <,<=,==
+        _imm = (int)ti.value();
+        assert _imm == ti.value();
+    }
+    CmpIX86( Node cmp, double ignore ) {
+        super(cmp);
+        _bop = "==";
+        _imm = 0;
+    }
+
+    @Override public RegMask regmap(int i) { assert i==1; return x86_64_v2.RMASK; }
+    @Override public RegMask outregmap() { return x86_64_v2.FLAGS_MASK; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    @Override public void asm(CodeGen code, SB sb) {
+        String dst = code.reg(this);
+        if( dst!="FLAGS" )  sb.p(dst).p(" = ");
+        sb.p(code.reg(in(1)));
+        if( _imm != 0 ) sb.p(", #").p(_imm);
+    }
+
+    @Override public String op() { return _imm==0 ? "test" : "cmp"; }
+
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpMemX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpMemX86.java
new file mode 100644
index 00000000..873ca9df
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpMemX86.java
@@ -0,0 +1,33 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.CodeGen;
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.node.*;
+
+public class CmpMemX86 extends MemOpX86 {
+    final boolean _invert;      // Op switched LHS, RHS
+    CmpMemX86( BoolNode bool, LoadNode ld , Node base, Node idx, int off, int scale, int imm, Node val, boolean invert ) {
+        super(bool,ld, base, idx, off, scale, imm, val );
+        _invert = invert;
+    }
+
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.FLAGS_MASK; }
+
+    // General form: "cmp  dst = src, [base + idx<<2 + 12]"
+    @Override public void asm(CodeGen code, SB sb) {
+        String dst = code.reg(this);
+        if( dst!="FLAGS" )  sb.p(dst).p(" = ");
+        if( _invert ) asm_address(code,sb).p(",");
+        if( val()==null ) {
+            if( _imm!=0 )  sb.p("#").p(_imm);
+        } else {
+            sb.p(code.reg(val()));
+        }
+        if( !_invert ) asm_address(code,sb.p(", "));
+    }
+
+    @Override public String op() { return ((val()==null && _imm==0) ? "test" : "cmp") + _sz; }
+
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpX86.java
new file mode 100644
index 00000000..6b502249
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CmpX86.java
@@ -0,0 +1,27 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class CmpX86 extends MachConcreteNode implements MachNode {
+    CmpX86( Node cmp ) { super(cmp); }
+
+    @Override public RegMask regmap(int i) { assert i==1 || i==2; return x86_64_v2.RMASK; }
+    @Override public RegMask outregmap() { return x86_64_v2.FLAGS_MASK; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "add  dst += src"
+    @Override public void asm(CodeGen code, SB sb) {
+        String dst = code.reg(this);
+        if( dst!="FLAGS" )  sb.p(dst).p(" = ");
+        sb.p(code.reg(in(1))).p(", ").p(code.reg(in(2)));
+    }
+
+    @Override public String op() { return "cmp"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivFX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivFX86.java
new file mode 100644
index 00000000..d73bfd5b
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivFX86.java
@@ -0,0 +1,33 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class DivFX86 extends MachConcreteNode implements MachNode {
+    DivFX86( Node divf) { super(divf); }
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) { assert i==1 || i==2; return x86_64_v2.XMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() {  return x86_64_v2.XMASK; }
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+
+    // General form: "divf  dst /= src"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" / ").p(code.reg(in(2)));
+    }
+
+    @Override public String op() {
+        // 8 bytes = 64 bits
+        return "divf";
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivX86.java
new file mode 100644
index 00000000..1dc20017
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivX86.java
@@ -0,0 +1,31 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class DivX86 extends MachConcreteNode implements MachNode {
+    DivX86( Node div ) { super(div); }
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) {
+        assert i==1 || i==2;
+        return x86_64_v2.RMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "div  dst /= src"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" / ").p(code.reg(in(2)));
+    }
+
+    @Override public String op() { return "div"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FltX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FltX86.java
new file mode 100644
index 00000000..21529f7b
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FltX86.java
@@ -0,0 +1,36 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.CodeGen;
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.Utils;
+import com.seaofnodes.simple.node.ConstantNode;
+import com.seaofnodes.simple.node.MachNode;
+
+import java.io.ByteArrayOutputStream;
+
+public class FltX86 extends ConstantNode implements MachNode {
+    FltX86(ConstantNode con ) { super(con); }
+
+    // Register mask allowed on input i.  0 for no register.
+    @Override public RegMask regmap(int i) { return RegMask.EMPTY; }
+    // General int registers
+    @Override public RegMask outregmap() { return x86_64_v2.XMASK; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // Human-readable form appended to the SB.  Things like the encoding,
+    // indentation, leading address or block labels not printed here.
+    // Just something like "ld4\tR17=[R18+12] // Load array base".
+    // General form: "op\tdst=src+src"
+    @Override public void asm(CodeGen code, SB sb) {
+        _con.print(sb.p(code.reg(this)).p(" #"));
+    }
+
+    @Override public String op() {
+        return "fld";           // Some fancier encoding
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FunX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FunX86.java
new file mode 100644
index 00000000..f969fae4
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FunX86.java
@@ -0,0 +1,21 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.Utils;
+import com.seaofnodes.simple.node.FunNode;
+import com.seaofnodes.simple.node.MachNode;
+import java.io.ByteArrayOutputStream;
+
+public class FunX86 extends FunNode implements MachNode {
+    FunX86( FunNode fun ) { super(fun); }
+
+    // Register mask allowed on input i.  0 for no register.
+    @Override public RegMask regmap(int i) { return RegMask.EMPTY; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return RegMask.EMPTY; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/I2f8X86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/I2f8X86.java
new file mode 100644
index 00000000..983f817d
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/I2f8X86.java
@@ -0,0 +1,28 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class I2f8X86 extends MachConcreteNode implements MachNode {
+    I2f8X86(Node i2f8 ) { super(i2f8); }
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) { assert i==1; return x86_64_v2.WMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.XMASK; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "i2f8 (flt)int_value"
+
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p("(flt)").p(code.reg(in(1)));
+    }
+
+    @Override public String op() { return "i2f8"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/IntX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/IntX86.java
new file mode 100644
index 00000000..2cd27c14
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/IntX86.java
@@ -0,0 +1,45 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.ConstantNode;
+import com.seaofnodes.simple.node.MachNode;
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.type.TypeInteger;
+
+import java.io.ByteArrayOutputStream;
+
+// Integer constants
+public class IntX86 extends ConstantNode implements MachNode {
+
+    IntX86( ConstantNode con ) {
+        super(con);
+    }
+
+    // Register mask allowed on input i.  0 for no register.
+    @Override public RegMask regmap(int i) { return RegMask.EMPTY; }
+    // General int registers
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // Human-readable form appended to the SB.  Things like the encoding,
+    // indentation, leading address or block labels not printed here.
+    // Just something like "ld4\tR17=[R18+12] // Load array base".
+    // General form: "op\tdst=src+src"
+    @Override public void asm(CodeGen code, SB sb) {
+        String reg = code.reg(this);
+        if( _con == Type.NIL || _con == TypeInteger.ZERO )
+            sb.p(reg).p(",").p(reg);
+        else
+            _con.print(sb.p(reg).p(" #"));
+    }
+
+    @Override public String op() {
+        if( _con == Type.NIL || _con == TypeInteger.ZERO )
+            return "xor";
+        return "ldi";           // Some fancier encoding
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java
new file mode 100644
index 00000000..7cf4444c
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java
@@ -0,0 +1,46 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+// Jump on flags, uses flags
+public class JmpX86 extends IfNode implements MachNode {
+    final String _bop;
+    JmpX86( IfNode iff, String bop ) {
+        super(iff);
+        _bop = bop;
+    }
+
+    @Override public String label() { return op(); }
+
+    @Override public void postSelect() {
+        Node set = in(1);
+        Node cmp = set.in(1);
+        // Bypass an expected Set and just reference the cmp directly
+        if( set instanceof SetX86 && (cmp instanceof CmpX86 || cmp instanceof CmpIX86 || cmp instanceof CmpMemX86) )
+            _inputs.set(1,cmp);
+        else
+            throw Utils.TODO();
+    }
+    @Override public RegMask regmap(int i) { assert i==1; return x86_64_v2.FLAGS_MASK; }
+    @Override public RegMask outregmap() { return RegMask.EMPTY; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    @Override public void asm(CodeGen code, SB sb) {
+        String src = code.reg(in(1));
+        if( src!="FLAGS" )  sb.p(src);
+    }
+
+    @Override public String op() { return "j"+_bop; }
+
+    @Override public String comment() {
+        return "L"+cproj(1)._nid+", L"+cproj(0)._nid;
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/LeaX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/LeaX86.java
new file mode 100644
index 00000000..a49b8d7f
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/LeaX86.java
@@ -0,0 +1,42 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class LeaX86 extends MachConcreteNode implements MachNode {
+    final int _scale;
+    final long _offset;
+    LeaX86( Node add, Node base, Node idx, int scale, long offset ) {
+        super(add);
+        assert scale==1 || scale==2 || scale==4 || scale==8;
+        _inputs.pop();
+        _inputs.pop();
+        _inputs.push(base);
+        _inputs.push(idx);
+        _scale = scale;
+        _offset = offset;
+    }
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) { assert i==1 || i==2; return x86_64_v2.RMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "lea  dst = base + 4*idx + 12"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ");
+        if( in(1) != null )
+            sb.p(code.reg(in(1))).p(" + ");
+        sb.p(code.reg(in(2))).p("*").p(_scale);
+        if( _offset!=0 ) sb.p(" + #").p(_offset);
+    }
+
+    @Override public String op() { return "lea"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/LoadX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/LoadX86.java
new file mode 100644
index 00000000..02a9a4fe
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/LoadX86.java
@@ -0,0 +1,25 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.CodeGen;
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.node.LoadNode;
+import com.seaofnodes.simple.node.Node;
+
+public class LoadX86 extends MemOpX86 {
+    LoadX86( LoadNode ld, Node base, Node idx, int off, int scale ) {
+        super(ld,ld, base, idx, off, scale, 0);
+    }
+
+    @Override public String op() { return "ld"+_sz; }
+
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+
+    // General form: "ldN  dst,[base + idx<<2 + 12]"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(",");
+        asm_address(code,sb);
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemAddX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemAddX86.java
new file mode 100644
index 00000000..418f63f3
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemAddX86.java
@@ -0,0 +1,28 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.CodeGen;
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.node.*;
+
+public class MemAddX86 extends MemOpX86 {
+    MemAddX86( StoreNode st, Node base, Node idx, int off, int scale, int imm, Node val ) {
+        super(st, st, base, idx, off, scale, imm, val );
+    }
+
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return RegMask.EMPTY; }
+
+
+    // General form: "add  [base + idx<<2 + 12] += src"
+    @Override public void asm(CodeGen code, SB sb) {
+        asm_address(code,sb);
+        if( val()==null ) {
+            if( _imm != 1 && _imm != -1 ) sb.p(" += #").p(_imm);
+        } else sb.p(" += ").p(code.reg(val()));
+    }
+
+    @Override public String op() {
+        return (_imm == 1 ? "inc" : (_imm == -1 ? "dec" : "add")) + _sz;
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java
new file mode 100644
index 00000000..1e678a0b
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java
@@ -0,0 +1,87 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.*;
+import java.io.ByteArrayOutputStream;
+import java.lang.StringBuilder;
+import java.util.BitSet;
+
+// Generic X86 memory operand base.
+// inputs:
+//   ctrl     - will appear for possibly RCE (i.e. array ops)
+//   mem      - memory dependence edge
+//   base     - Basic object pointer
+//   idx/null - Scaled index offset, or null if none
+//   val/null - Value to store, as part of a op-to-mem or op-from-mem.  Null for loads, or if an immediate is being used
+// Constants:
+//   offset   - offset added to base.  Can be zero.
+//   scale    - scale on index; only 0,1,2,4,8 allowed, 0 is only when index is null
+//   imm      - immediate value to store or op-to-mem, and only when val is null
+public abstract class MemOpX86 extends MemOpNode implements MachNode {
+    final int _off;             // Limit 32 bits
+    final int _scale;           // Limit 0,1,2,3
+    final int _imm;             // Limit 32 bits
+    final char _sz = (char)('0'+(1<<_declaredType.log_size()));
+    MemOpX86( Node op, MemOpNode mop, Node base, Node idx, int off, int scale, int imm ) {
+        super(op,mop);
+        assert base._type instanceof TypeMemPtr && !(base instanceof AddNode);
+        assert (idx==null && scale==0) || (idx!=null && 0<= scale && scale<=3);
+
+        // Copy memory parts from eg the LoadNode over the opcode, e.g. an Add
+        if( op != mop ) {
+            _inputs.set(0,mop.in(0)); // Control from mem op
+            _inputs.set(1,mop.in(1)); // Memory  from mem op
+            _inputs.set(2,base);      // Base handed in
+        }
+
+        assert ptr() == base;
+        _inputs.setX(3,idx);
+        _off = off;
+        _scale = scale;
+        _imm = imm;
+    }
+
+    // Store-based flavors have a value edge
+    MemOpX86( Node op, MemOpNode mop, Node base, Node idx, int off, int scale, int imm, Node val ) {
+        this(op,mop,base,idx,off,scale,imm);
+        _inputs.setX(4,val);
+    }
+
+    Node idx() { return in(3); }
+    Node val() { return in(4); }
+
+    @Override public  StringBuilder _printMach(StringBuilder sb, BitSet visited) { return sb.append(".").append(_name); }
+
+    @Override public String label() { return op(); }
+    @Override public Type compute() { throw Utils.TODO(); }
+    @Override public Node idealize() { throw Utils.TODO(); }
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) {
+        if( i==1 ) return RegMask.EMPTY;    // Memory
+        if( i==2 ) return x86_64_v2.RMASK;  // base
+        if( i==3 ) return x86_64_v2.RMASK;  // index
+        if( i==4 ) return x86_64_v2.RMASK;  // value
+        throw Utils.TODO();
+    }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { throw Utils.TODO(); }
+
+    @Override public int encoding(ByteArrayOutputStream bytes) { throw Utils.TODO(); }
+
+
+    // "[base + idx<<2 + 12]"
+    SB asm_address(CodeGen code, SB sb) {
+        sb.p("[").p(code.reg(ptr()));
+        if( idx() != null ) {
+            sb.p("+").p(code.reg(idx()));
+            if( _scale != 0 )
+                sb.p("<<").p(_scale);
+        }
+        if( _off != 0 )
+            sb.p("+").p(_off);
+        return sb.p("]");
+    }
+
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulFX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulFX86.java
new file mode 100644
index 00000000..aef813e1
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulFX86.java
@@ -0,0 +1,30 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeFloat;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class MulFX86 extends MachConcreteNode implements MachNode {
+    MulFX86( Node mulf) { super(mulf); }
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) { assert i==1 || i==2; return x86_64_v2.XMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.XMASK; }
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "mulf  dst *= src"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" * ").p(code.reg(in(2)));
+    }
+
+    @Override public String op() { return "mulf"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulIX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulIX86.java
new file mode 100644
index 00000000..7508cf4c
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulIX86.java
@@ -0,0 +1,36 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class MulIX86 extends MachConcreteNode  implements MachNode {
+    final TypeInteger _ti;
+    MulIX86(Node mul, TypeInteger ti) {super(mul); _inputs.pop(); _ti = ti;}
+
+    // Register mask allowed on input i.
+    // This is the normal calling convention
+    @Override public RegMask regmap(int i) {
+        // assert i==1;
+        return x86_64_v2.WMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+    // General form
+    // General form: "muli  dst * #imm"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" * #");
+        _ti.print(sb);
+    }
+
+    @Override public String op() { return "muli"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulX86.java
new file mode 100644
index 00000000..15fd9496
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulX86.java
@@ -0,0 +1,30 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class MulX86 extends MachConcreteNode implements MachNode {
+
+    MulX86( Node mul ) { super(mul); }
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) { assert i==1 || i==2; return x86_64_v2.RMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "mul  dst *= src"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" * ").p(code.reg(in(2)));
+    }
+
+    @Override public String op() { return "mul"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NewX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NewX86.java
new file mode 100644
index 00000000..4396a917
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NewX86.java
@@ -0,0 +1,40 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import java.io.ByteArrayOutputStream;
+
+public class NewX86 extends NewNode implements MachNode {
+
+    // A pre-zeroed chunk of memory.
+    NewX86( NewNode nnn ) {  super(nnn); }
+
+    // Register mask allowed on input i, the size
+    @Override public RegMask regmap(int i) {
+        // Size
+        if( i==1 ) return x86_64_v2.RDI_MASK;
+        // All the memory alias edges
+        return RegMask.EMPTY;
+    }
+    @Override public RegMask outregmap() { throw Utils.TODO(); }
+
+    // Register mask allowed as a result.  Pointer result in standard calling
+    // convention.
+    @Override public RegMask outregmap(int i) {
+        if( i == 1 ) return x86_64_v2.RET_MASK;
+        // All the memory aliases edges
+        return RegMask.EMPTY;
+    }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "alloc #bytes"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(size()));
+    }
+
+    @Override public String op() { return "alloc"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/OrIX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/OrIX86.java
new file mode 100644
index 00000000..513962c2
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/OrIX86.java
@@ -0,0 +1,44 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.CodeGen;
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.Utils;
+import com.seaofnodes.simple.node.MachConcreteNode;
+import com.seaofnodes.simple.node.MachNode;
+import com.seaofnodes.simple.node.Node;
+import com.seaofnodes.simple.type.TypeInteger;
+
+import java.io.ByteArrayOutputStream;
+
+public class OrIX86  extends MachConcreteNode implements MachNode {
+
+    final TypeInteger _ti;
+    OrIX86(Node or, TypeInteger ti) {super(or);  _inputs.pop(); _ti = ti;}
+
+    // Register mask allowed on input i.
+    // This is the normal calling convention
+    @Override public RegMask regmap(int i) {
+        //assert i==1;
+        return x86_64_v2.WMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form
+    // General form: "ori  ori | #imm"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" | #");
+        _ti.print(sb);
+    }
+
+    @Override public String op() { return "ori"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ParmX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ParmX86.java
new file mode 100644
index 00000000..8a439644
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ParmX86.java
@@ -0,0 +1,24 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.Utils;
+import com.seaofnodes.simple.node.ParmNode;
+import com.seaofnodes.simple.node.MachNode;
+import java.io.ByteArrayOutputStream;
+
+public class ParmX86 extends ParmNode implements MachNode {
+    final RegMask _rmask;
+    ParmX86( ParmNode parm ) {
+        super(parm);
+        _rmask = x86_64_v2.callInMask(_idx);
+    }
+
+    // Register mask allowed on input i.  0 for no register.
+    @Override public RegMask regmap(int i) { return RegMask.EMPTY; }
+    // Register mask allowed as a result.  Calling convention register
+    @Override public RegMask outregmap() { return _rmask; }
+
+    // Encoding is appended into the byte array.  Returns size
+    @Override public int encoding(ByteArrayOutputStream bytes) { return 0; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ProjX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ProjX86.java
new file mode 100644
index 00000000..2849b232
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ProjX86.java
@@ -0,0 +1,23 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.Utils;
+import com.seaofnodes.simple.node.ProjNode;
+import com.seaofnodes.simple.node.MachNode;
+import java.io.ByteArrayOutputStream;
+
+public class ProjX86 extends ProjNode implements MachNode {
+
+    ProjX86( ProjNode p ) { super(p); }
+
+    // Register mask allowed on input i.  0 for no register.
+    @Override public RegMask regmap(int i) { return RegMask.EMPTY; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return RegMask.EMPTY; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/RetX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/RetX86.java
new file mode 100644
index 00000000..e6219ff4
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/RetX86.java
@@ -0,0 +1,48 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.FunNode;
+import com.seaofnodes.simple.node.ReturnNode;
+import com.seaofnodes.simple.node.MachNode;
+import java.io.ByteArrayOutputStream;
+
+// Return
+public class RetX86 extends ReturnNode implements MachNode {
+    RetX86( ReturnNode ret, FunNode fun ) { super(ret, fun); fun.setRet(this); }
+
+    // Correct Nodes outside the normal edges
+    @Override public void postSelect() {
+        FunNode fun = (FunNode)rpc().in(0);
+        _fun = fun;
+        fun.setRet(this);
+    }
+
+    // Register mask allowed on input i.
+    // This is the normal calling convention
+    @Override public RegMask regmap(int i) {
+        return switch( i ) {
+        case 0 -> RegMask.EMPTY;
+        case 1 -> RegMask.EMPTY;
+        case 2 -> x86_64_v2.RET_MASK;
+        case 3 -> RegMask.EMPTY; // RPC is always on stack
+        default -> throw Utils.TODO();
+        };
+    }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return RegMask.EMPTY; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // Human-readable form appended to the SB.  Things like the encoding,
+    // indentation, leading address or block labels not printed here.
+    // Just something like "ld4\tR17=[R18+12] // Load array base".
+    // General form: "op\tdst=src+src"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(in(2)));
+    }
+
+    @Override public String op() { return "ret"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SarX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SarX86.java
new file mode 100644
index 00000000..3d907eef
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SarX86.java
@@ -0,0 +1,40 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+import java.util.BitSet;
+import java.lang.StringBuilder;
+
+
+public class SarX86 extends MachConcreteNode implements MachNode {
+    final TypeInteger _ti;
+    SarX86(Node sar, TypeInteger ti) {super(sar); _inputs.pop();  _ti = ti;}
+
+    // Register mask allowed on input i.
+    // This is the normal calling convention
+    @Override public RegMask regmap(int i) {
+        // assert i==1;
+        return x86_64_v2.RMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form
+    // General form: "sari  dst << #imm"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" >> #");
+        _ti.print(sb);
+    }
+
+    @Override public String op() { return "sari"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java
new file mode 100644
index 00000000..25367e03
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java
@@ -0,0 +1,39 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+// Compare immediate.  Sets flags.
+// Corresponds to the x86 instruction "sete && setne".
+// Use result of comparison without jump.
+public class SetX86 extends MachConcreteNode implements MachNode {
+    final String _bop;          // One of <,<=,==
+    // Constructor expects input is an X86 and not an Ideal node.
+    SetX86( Node cmp, String bop ) {
+        super(cmp);
+        _inputs.setLen(1);   // Pop the cmp inputs
+        // Replace with the matched cmp
+        _inputs.push(cmp);
+        _bop = bop;
+    }
+
+    @Override public RegMask regmap(int i) { assert i==1; return x86_64_v2.FLAGS_MASK; }
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this));
+        String src = code.reg(in(1));
+        if( src!="FLAGS" )  sb.p(" = ").p(src);
+    }
+
+    @Override public String op() { return "set"+_bop; }
+
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ShlIX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ShlIX86.java
new file mode 100644
index 00000000..61e0d262
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ShlIX86.java
@@ -0,0 +1,38 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+import java.util.BitSet;
+
+public class ShlIX86 extends MachConcreteNode implements MachNode{
+    final TypeInteger _ti;
+    ShlIX86(Node shl, TypeInteger ti) {super(shl); _inputs.pop(); _ti = ti;}
+
+    // Register mask allowed on input i.
+    // This is the normal calling convention
+    @Override public RegMask regmap(int i) {
+        //assert i==1;
+        return x86_64_v2.RMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form
+    // General form: "shli  dst << #imm"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" << #");
+        _ti.print(sb);
+    }
+
+    @Override public String op() { return "shli"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ShrIX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ShrIX86.java
new file mode 100644
index 00000000..08cae93e
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/ShrIX86.java
@@ -0,0 +1,39 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+import java.util.BitSet;
+import java.lang.StringBuilder;
+
+public class ShrIX86 extends MachConcreteNode implements MachNode{
+    final TypeInteger _ti;
+    ShrIX86(Node shr, TypeInteger ti) {super(shr); _inputs.pop(); _ti = ti;}
+
+    // Register mask allowed on input i.
+    // This is the normal calling convention
+    @Override public RegMask regmap(int i) {
+        //assert i==1;
+        return x86_64_v2.RMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form
+    // General form: "shri  dst >>> #imm"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" >>> #");
+        _ti.print(sb);
+    }
+
+    @Override public String op() { return "shri"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/StoreX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/StoreX86.java
new file mode 100644
index 00000000..c9191b87
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/StoreX86.java
@@ -0,0 +1,30 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.CodeGen;
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.node.Node;
+import com.seaofnodes.simple.node.StoreNode;
+import java.util.BitSet;
+
+public class StoreX86 extends MemOpX86 {
+    StoreX86( StoreNode st, Node base, Node idx, int off, int scale, int imm, Node val ) {
+        super(st,st, base, idx, off, scale, imm, val);
+    }
+
+    @Override public String op() { return "st"+_sz; }
+
+    @Override public StringBuilder _printMach(StringBuilder sb, BitSet visited) {
+        return sb.append(".").append(_name).append("=").append(val()==null ? _imm : val()).append(";");
+    }
+
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return RegMask.EMPTY; }
+
+    // General form: "stN  [base + idx<<2 + 12],val"
+    @Override public void asm(CodeGen code, SB sb) {
+        asm_address(code,sb).p(",");
+        if( val()==null ) sb.p("#").p(_imm);
+        else sb.p(code.reg(val()));
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubFX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubFX86.java
new file mode 100644
index 00000000..ed19ad79
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubFX86.java
@@ -0,0 +1,29 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import java.io.ByteArrayOutputStream;
+
+public class SubFX86 extends MachConcreteNode implements MachNode {
+    SubFX86( Node subf) {  super(subf); }
+
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) { assert i==1 || i==2; return x86_64_v2.XMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.XMASK; }
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "subf  dst -= src"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" - ").p(code.reg(in(2)));
+    }
+
+    @Override public String op() { return "subf"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubX86.java
new file mode 100644
index 00000000..cac59d3b
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubX86.java
@@ -0,0 +1,29 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import java.io.ByteArrayOutputStream;
+
+public class SubX86 extends MachConcreteNode implements MachNode {
+    SubX86( Node sub ) { super(sub); }
+
+    // Register mask allowed on input i.
+    @Override public RegMask regmap(int i) { assert i==1 || i==2; return x86_64_v2.RMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form: "sub  dst -= src"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" - ").p(code.reg(in(2)));
+    }
+
+    @Override public String op() { return "sub"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/TFPX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/TFPX86.java
new file mode 100644
index 00000000..bd88011f
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/TFPX86.java
@@ -0,0 +1,41 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.*;
+import com.seaofnodes.simple.node.ConstantNode;
+import com.seaofnodes.simple.node.MachNode;
+import com.seaofnodes.simple.type.Type;
+import com.seaofnodes.simple.type.TypeFunPtr;
+
+import java.io.ByteArrayOutputStream;
+
+// Function constants
+public class TFPX86 extends ConstantNode implements MachNode {
+    TFPX86( ConstantNode con ) {  super(con); }
+    // Register mask allowed on input i.  0 for no register.
+    @Override public RegMask regmap(int i) { return RegMask.EMPTY; }
+    // General int registers
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // Human-readable form appended to the SB.  Things like the encoding,
+    // indentation, leading address or block labels not printed here.
+    // Just something like "ld4\tR17=[R18+12] // Load array base".
+    // General form: "op\tdst=src+src"
+    @Override public void asm(CodeGen code, SB sb) {
+        String reg = code.reg(this);
+        if( _con == Type.NIL )
+            sb.p(reg).p(",").p(reg);
+        else
+            _con.print(sb.p(reg).p(" #"));
+    }
+
+    @Override public String op() {
+        if( _con == Type.NIL )
+            return "xor";
+        return "ldx";           // Some fancier encoding
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/XorIX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/XorIX86.java
new file mode 100644
index 00000000..795fa814
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/XorIX86.java
@@ -0,0 +1,42 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.CodeGen;
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.Utils;
+import com.seaofnodes.simple.node.MachConcreteNode;
+import com.seaofnodes.simple.node.MachNode;
+import com.seaofnodes.simple.node.Node;
+import com.seaofnodes.simple.type.TypeInteger;
+
+import java.io.ByteArrayOutputStream;
+
+public class XorIX86  extends MachConcreteNode implements MachNode {
+
+    final TypeInteger _ti;
+    XorIX86(Node xor, TypeInteger ti) {super(xor); _inputs.pop(); _ti = ti;}
+
+    // Register mask allowed on input i.
+    // This is the normal calling convention
+    @Override public RegMask regmap(int i) { assert i==1; return x86_64_v2.WMASK; }
+    // Register mask allowed as a result.  0 for no register.
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
+
+
+    // Output is same register as input#1
+    @Override public int twoAddress() { return 1; }
+
+    // Encoding is appended into the byte array; size is returned
+    @Override public int encoding(ByteArrayOutputStream bytes) {
+        throw Utils.TODO();
+    }
+
+    // General form
+    // General form: "ori  xori ^ #imm"
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" ^ #");
+        _ti.print(sb);
+    }
+
+    @Override public String op() { return "xori"; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
new file mode 100644
index 00000000..45ae19dc
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
@@ -0,0 +1,418 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.simple.CodeGen;
+import com.seaofnodes.simple.Machine;
+import com.seaofnodes.simple.RegMask;
+import com.seaofnodes.simple.Utils;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.*;
+
+public class x86_64_v2 extends Machine {
+    // X86-64 V2.  Includes e.g. SSE4.2 and POPCNT.
+    @Override public String name() { return "x86_64_v2"; }
+
+    public static int RAX =  0, RCX =  1, RDX =  2, RBX =  3, RSP =  4, RBP =  5, RSI =  6, RDI =  7;
+    public static int R08 =  8, R09 =  9, R10 = 10, R11 = 11, R12 = 12, R13 = 13, R14 = 14, R15 = 15;
+    public static int FLAGS = 32;
+
+    public static int XMM0  = 16, XMM1  = 17, XMM2  = 18, XMM3  = 19, XMM4  = 20, XMM5  = 21, XMM6  = 22, XMM7  = 23;
+    public static int XMM8  = 24, XMM9  = 25, XMM10 = 26, XMM11 = 27, XMM12 = 28, XMM13 = 29, XMM14 = 30, XMM15 = 31;
+
+    // General purpose register mask: pointers and ints, not floats
+    public static RegMask RMASK = new RegMask(0b1111111111111111);
+    // No RSP in the *write* general set.
+    public static RegMask WMASK = new RegMask(0b1111111111101111);
+    // Xmm register mask
+    public static RegMask XMASK = new RegMask( 0b1111111111111111L << XMM0);
+
+    public static RegMask FLAGS_MASK = new RegMask(1L<<FLAGS);
+
+    // Return single int/ptr register
+    public static RegMask RET_MASK = new RegMask(RAX);
+
+    public static RegMask RDI_MASK = new RegMask(1L<<RDI);
+    public static RegMask RCX_MASK = new RegMask(1L<<RCX);
+    public static RegMask RDX_MASK = new RegMask(1L<<RDX);
+    public static RegMask R08_MASK = new RegMask(1L<<R08);
+    public static RegMask R09_MASK = new RegMask(1L<<R09);
+    public static RegMask RSI_MASK = new RegMask(1L<<RSI);
+
+    // Calling conv metadata
+    public int GPR_COUNT_CONV_WIN64 = 4; // RCX, RDX, R9, R9
+    public int XMM_COUNT_CONV_WIN64 = 4; // XMM0L, XMM1L, XMM2L, XMM3L
+
+    public int GPR_COUNT_CONV_SYSTEM_V = 6; // RDI, RSI, RDX, RCX, R8, R9
+    public int XMM_COUNT_CONV_SYSTEM_V = 4; // XMM0, XMM1, XMM2, XMM3 ....
+    // Human-readable name for a register number, e.g. "RAX".
+    // Hard crash for bad register number, fix yer bugs!
+    public static final String[] REGS = new String[] {
+        "rax" , "rcx" , "rdx"  , "rbx"  , "rsp"  , "rbp"  , "rsi"  , "rdi"  ,
+        "r8"  , "r9"  , "r10"  , "r11"  , "r12"  , "r13"  , "r14"  , "r15"  ,
+        "xmm0", "xmm1", "xmm2" , "xmm3" , "xmm4" , "xmm5" , "xmm6" , "xmm7" ,
+        "xmm8", "xmm9", "xmm10", "xmm11", "xmm12", "xmm13", "xmm14", "xmm15",
+    };
+    @Override public String reg( int reg ) { return REGS[reg]; }
+
+    // Calling convention; returns a machine-specific register
+    // for incoming argument idx.
+    // index 0 for control, 1 for memory, real args start at index 2
+    static int callInArg( int idx ) {
+        return switch( CodeGen.CODE._callingConv ) {
+        case CodeGen.CallingConv.SystemV -> callInArgSystemV(idx);
+        case CodeGen.CallingConv.Win64   -> callInArgWin64  (idx);
+        };
+    }
+
+    // WIN64(param passing)
+    static RegMask[] CALLINMASK_WIN64 = new RegMask[] {
+        RegMask.EMPTY,
+        RegMask.EMPTY,
+        RCX_MASK,
+        RDX_MASK,
+        R08_MASK,
+        R09_MASK,
+        RegMask.EMPTY,
+        RegMask.EMPTY
+    };
+    static int[] CALLINARG_WIN64 = new int[] {
+        0,   // Control, no register
+        0,   // Memory, no register
+        RCX, //
+        RDX,
+        R08,
+        R09,
+        0,
+        0,
+    };
+    static int callInArgWin64( int idx ) { return CALLINARG_WIN64[idx]; }
+
+    // caller saved(win64)
+    public static final long WIN64_ABI_CALLER_SAVED =
+        (1L << RAX) | (1L << RCX) | (1L << RDX) | (1L << R08) | (1L << R09) | (1L << R10) | (1L << R11);
+
+    // callee saved(win64)
+    public static final long WIN64_ABI_CALLEE_SAVED = ~WIN64_ABI_CALLER_SAVED;
+
+    // SystemV(param passing)
+    static RegMask[] CALLINMASK_SYSTEMV = new RegMask[] {
+        RegMask.EMPTY,
+        RegMask.EMPTY,
+        RDI_MASK,
+        RSI_MASK,
+        RDX_MASK,
+        RCX_MASK,
+        R08_MASK,
+        R09_MASK
+    };
+    static int[] CALLINARG_SYSTEMV = new int[] {
+        0,   // Control, no register
+        0,   // Memory, no register
+        RDI,
+        RSI,
+        RDX,
+        RCX,
+        R08,
+        R09,
+    };
+    static int callInArgSystemV( int idx ) { return CALLINARG_SYSTEMV[idx]; }
+
+    // caller saved(systemv)
+    // caller saved(win64)
+    public static final long SYSTEMV_ABI_CALLER_SAVED =
+        (1L << RAX) | (1L << RDI) | (1L << RSI) | (1L << RCX) | (1L << RDX) | (1L << R08) | (1L << R09) << (1L << R10) << (1L << R11);
+    // callee saved(systemv)
+    public static final long SYSTEMV_ABI_CALLE_SAVED = ~SYSTEMV_ABI_CALLER_SAVED;
+
+
+    static RegMask callInMask( int idx ) {
+        return switch( CodeGen.CODE._callingConv ) {
+        case CodeGen.CallingConv.SystemV -> CALLINMASK_SYSTEMV[idx];
+        case CodeGen.CallingConv.Win64   -> CALLINMASK_WIN64  [idx];
+        };
+    }
+
+    // Create a split op; any register to any register, including stack slots
+    @Override public Node split() {
+        throw Utils.TODO();
+    }
+
+    // Return a MachNode unconditional branch
+    @Override public CFGNode jump() {
+        throw Utils.TODO();
+    }
+
+    // Break an infinite loop
+    @Override public IfNode never( CFGNode ctrl ) {
+        throw Utils.TODO();
+    }
+
+    // Instruction selection
+    @Override public Node instSelect( Node n ) {
+        return switch( n ) {
+        case AddFNode     addf  -> addf(addf);
+        case AddNode      add   -> add(add);
+        case AndNode      and   -> and(and);
+        case BoolNode     bool  -> cmp(bool);
+        case CallEndNode  cend  -> new CallEndNode((CallNode)cend.in(0));
+        case CallNode     call  -> call(call);
+        case CProjNode    c     -> new CProjNode(c);
+        case ConstantNode con   -> con(con);
+        case DivFNode     divf  -> new DivFX86(divf);
+        case DivNode      div   -> new DivX86(div);
+        case FunNode      fun   -> new FunX86(fun);
+        case IfNode       iff   -> jmp(iff);
+        case LoadNode     ld    -> ld(ld);
+        case MemMergeNode mem   -> new MemMergeNode(mem);
+        case MulFNode     mulf  -> new MulFX86(mulf);
+        case MulNode      mul   -> mul(mul);
+        case NewNode      nnn   -> new NewX86(nnn);
+        case OrNode       or   ->  or(or);
+        case ParmNode     parm  -> new ParmX86(parm);
+        case PhiNode      phi   -> new PhiNode(phi);
+        case ProjNode     prj   -> prj(prj);
+        case ReadOnlyNode read  -> new ReadOnlyNode(read);
+        case ReturnNode   ret   -> new RetX86(ret,ret.fun());
+        case SarNode      sar   -> sar(sar);
+        case ShlNode      shl   -> shl(shl);
+        case ShrNode      shr   -> shr(shr);
+        case StartNode    start -> new StartNode(start);
+        case StopNode     stop  -> new StopNode(stop);
+        case StoreNode    st    -> st(st);
+        case SubFNode     subf  -> new SubFX86(subf);
+        case SubNode      sub   -> sub(sub);
+        case ToFloatNode  tfn   -> i2f8(tfn);
+        case XorNode      xor   -> xor(xor);
+
+        case LoopNode     loop  -> new LoopNode(loop);
+        case RegionNode   region-> new RegionNode(region);
+        default -> throw Utils.TODO();
+        };
+    }
+
+
+    // Attempt a full LEA-style break down.
+    private Node add( AddNode add ) {
+        Node lhs = add.in(1);
+        Node rhs = add.in(2);
+        if( lhs instanceof LoadNode ld && ld.nOuts()==1 )
+            return new AddMemX86(add,address(ld),ld.ptr(),idx,off,scale, imm(rhs),val);
+
+        if( rhs instanceof LoadNode ld && ld.nOuts()==1 )
+            throw Utils.TODO(); // Swap load sides
+
+        // Attempt a full LEA-style break down.
+        // Returns one of AddX86, AddIX86, LeaX86, or LHS
+        if( rhs instanceof ConstantNode off && off._con instanceof TypeInteger toff ) {
+            if( lhs instanceof AddNode ladd )
+                // ((base + (idx << scale)) + off)
+                return _lea(add,ladd.in(1),ladd.in(2),toff.value());
+            if( lhs instanceof ShlNode shift )
+                // (idx << scale) + off; no base
+                return _lea(add,null,shift,toff.value());
+
+            // lhs + rhs1
+            if( toff.value()==0 ) return add;
+            return new AddIX86(add, toff);
+        }
+        return _lea(add,lhs,rhs,0);
+    }
+
+
+    private Node addf( AddFNode addf ) {
+        if( addf.in(1) instanceof LoadNode ld && ld.nOuts()==1 )
+            return new AddFMemX86(addf,address(ld),ld.ptr(),idx,off,scale, addf.in(2));
+
+        if( addf.in(2) instanceof LoadNode ld && ld.nOuts()==1 )
+            throw Utils.TODO(); // Swap load sides
+
+        return new AddFX86(addf);
+    }
+
+
+    private Node _lea( Node add, Node base, Node idx, long off ) {
+        int scale = 1;
+        if( base instanceof ShlNode && !(idx instanceof ShlNode) ) throw Utils.TODO(); // Bug in canonicalization, should on RHS
+        if( idx instanceof ShlNode shift && shift.in(2) instanceof ConstantNode shfcon &&
+            shfcon._con instanceof TypeInteger tscale && 0 <= tscale.value() && tscale.value() <= 3 ) {
+            idx = shift.in(1);
+            scale = 1 << ((int)tscale.value());
+        }
+        // (base + idx) + off
+        return off==0 && scale==1
+            ? new AddX86(add)
+            : new LeaX86(add,base,idx,scale,off);
+    }
+
+
+    private Node and(AndNode and) {
+        if( and.in(2) instanceof ConstantNode con && con._con instanceof TypeInteger ti )
+            return new AndIX86(and, ti);
+        throw Utils.TODO();
+    }
+
+    private Node call(CallNode call) {
+        if( call.fptr() instanceof ConstantNode con && con._con instanceof TypeFunPtr tfp )
+            return new CallX86(call, tfp);
+        return new CallRX86( call );
+    }
+
+    // Because X86 flags, a normal ideal Bool is 2 X86 ops: a "cmp" and at "setz".
+    // Ideal If reading from a setz will skip it and use the "cmp" instead.
+    private Node cmp( BoolNode bool ) {
+        Node cmp = _cmp(bool);
+        return new SetX86(cmp,bool.op());
+    }
+    private Node _cmp( BoolNode bool ) {
+        Node lhs = bool.in(1);
+        Node rhs = bool.in(2);
+        if( lhs instanceof LoadNode ld && ld.nOuts()==1 )
+            return new CmpMemX86(bool,address(ld),ld.ptr(),idx,off,scale, imm(rhs),val,false);
+
+        if( rhs instanceof LoadNode ld && ld.nOuts()==1 )
+            return new CmpMemX86(bool,address(ld),ld.ptr(),idx,off,scale, imm(lhs),val,true);
+
+        return rhs instanceof ConstantNode con && con._con instanceof TypeInteger ti
+            ? new CmpIX86(bool, ti)
+            : new  CmpX86(bool);
+    }
+
+    private Node con( ConstantNode con ) {
+        return switch( con._con ) {
+        case TypeInteger ti  -> new IntX86(con);
+        case TypeFloat   tf  -> new FltX86(con);
+        case TypeFunPtr  tfp -> new TFPX86(con);
+        case TypeMemPtr  tmp -> new ConstantNode(con);
+        case TypeNil     tn  -> throw Utils.TODO();
+        // TOP, BOTTOM, XCtrl, Ctrl, etc.  Never any executable code.
+        case Type t -> new ConstantNode(con);
+        };
+    }
+
+    private Node i2f8(ToFloatNode tfn) {
+        assert tfn.in(1)._type instanceof TypeInteger ti;
+        return new I2f8X86(tfn);
+    }
+
+    private Node jmp( IfNode iff ) {
+        // If/Bool combos will match to a Cmp/Set which sets flags.
+        // Most general arith ops will also set flags, which the Jmp needs directly.
+        // Loads do not set the flags, and will need an explicit TEST
+        if( !(iff.in(1) instanceof BoolNode) )
+            iff.setDef(1,new BoolNode.EQ(iff.in(1),new ConstantNode(TypeInteger.ZERO)));
+        return new JmpX86(iff, ((BoolNode)iff.in(1)).op());
+    }
+
+    private Node ld( LoadNode ld ) {
+        return new LoadX86(address(ld),ld.ptr(),idx,off,scale);
+    }
+
+    private Node mul(MulNode mul) {
+        return mul.in(2) instanceof ConstantNode con && con._con instanceof TypeInteger ti
+            ? new MulIX86(mul, ti)
+            : new MulX86(mul);
+    }
+
+    private Node or(OrNode or) {
+        if( or.in(2) instanceof ConstantNode con && con._con instanceof TypeInteger ti)
+            return new OrIX86(or, ti);
+        throw Utils.TODO();
+    }
+
+    private Node prj( ProjNode prj ) {
+        return new ProjX86(prj);
+    }
+
+    private Node sar( SarNode sar ) {
+        if( sar.in(2) instanceof ConstantNode con && con._con instanceof TypeInteger ti)
+            return new SarX86(sar, ti);
+        throw Utils.TODO();
+    }
+
+    private Node shl( ShlNode shl ) {
+        if( shl.in(2) instanceof ConstantNode con && con._con instanceof TypeInteger ti )
+            return new ShlIX86(shl, ti);
+        throw Utils.TODO();
+    }
+
+    private Node shr(ShrNode shr) {
+        if( shr.in(2) instanceof ConstantNode con && con._con instanceof TypeInteger ti )
+            return new ShrIX86(shr, ti);
+        throw Utils.TODO();
+    }
+
+    private Node st( StoreNode st ) {
+        // Look for "*ptr op= val"
+        Node op = st.val();
+        if( op instanceof AddNode ) {
+            if( op.in(1) instanceof LoadNode ld &&
+                ld.in(0)==st.in(0) &&
+                ld.mem()==st.mem() &&
+                ld.ptr()==st.ptr() &&
+                ld.off()==st.off() ) {
+                if( op instanceof AddNode ) {
+                    return new MemAddX86(address(st),st.ptr(),idx,off,scale,imm(op.in(2)),val);
+                }
+                throw Utils.TODO();
+            }
+        }
+
+        return new StoreX86(address(st),st.ptr(),idx,off,scale,imm(st.val()),val);
+    }
+
+    private Node sub( SubNode sub ) {
+        return sub.in(2) instanceof ConstantNode con && con._con instanceof TypeInteger ti
+            ? new AddIX86(sub, TypeInteger.constant(-ti.value()))
+            : new SubX86(sub);
+    }
+
+    private Node xor(XorNode xor) {
+        if(xor.in(2) instanceof ConstantNode con && con._con instanceof TypeInteger ti)
+            return new XorIX86(xor, ti);
+        throw Utils.TODO();
+    }
+
+
+    // Gather X86 addressing mode bits prior to constructing.  This is a
+    // builder pattern, but saving the bits in a *local* *global* here to keep
+    // mess contained.
+    private static int off, scale, imm;
+    private static Node idx, val;
+    private <N extends MemOpNode> N address( N mop ) {
+        off = scale = imm = 0;  // Reset
+        idx = val = null;
+        Node base = mop.ptr();
+        // Skip/throw-away a ReadOnly, only used to typecheck
+        if( base instanceof ReadOnlyNode read ) base = read.in(1);
+        assert !(base instanceof AddNode) && base._type instanceof TypeMemPtr; // Base ptr always, not some derived
+        if( mop.off() instanceof AddNode add && add.in(2) instanceof ConstantNode con && con._con instanceof TypeInteger ti ) {
+            off = (int)ti.value();
+            assert off == ti.value(); // In 32-bit range
+            idx = add.in(1);
+            if( idx instanceof ShlNode shift && shift.in(2) instanceof ConstantNode shfcon &&
+                shfcon._con instanceof TypeInteger tscale && 0 <= tscale.value() && tscale.value() <= 3 ) {
+                idx = shift.in(1);
+                scale = (int)tscale.value();
+            }
+        } else {
+            if( mop.off() instanceof ConstantNode con && con._con instanceof TypeInteger ti ) {
+                off = (int)ti.value();
+                assert off == ti.value(); // In 32-bit range
+            } else {
+                idx = mop.off();
+            }
+        }
+        return mop;
+    }
+    private int imm( Node xval ) {
+        assert val==null && imm==0;
+        if( xval instanceof ConstantNode con && con._con instanceof TypeInteger ti ) {
+            val = null;
+            imm = (int)ti.value();
+            assert imm == ti.value(); // In 32-bit range
+        } else {
+            val = xval;
+        }
+        return imm;
+    }
+
+}
diff --git a/src/main/java/com/seaofnodes/simple/type/Type.java b/src/main/java/com/seaofnodes/simple/type/Type.java
index b6757ef2..847235dd 100644
--- a/src/main/java/com/seaofnodes/simple/type/Type.java
+++ b/src/main/java/com/seaofnodes/simple/type/Type.java
@@ -232,8 +232,4 @@ public class Type {
 
     // This is used by error messages, and is a shorted print.
     public String str() { return STRS[_type]; }
-
-    public static void reset() {
-        TypeFunPtr.reset();
-    }
 }
diff --git a/src/main/java/com/seaofnodes/simple/type/TypeFunPtr.java b/src/main/java/com/seaofnodes/simple/type/TypeFunPtr.java
index cf92d3d7..be801c85 100644
--- a/src/main/java/com/seaofnodes/simple/type/TypeFunPtr.java
+++ b/src/main/java/com/seaofnodes/simple/type/TypeFunPtr.java
@@ -25,7 +25,6 @@ public class TypeFunPtr extends TypeNil {
     // within the TypeTuple.  Can be upgraded to a BitSet for larger classes of
     // functions.  Negative means "these 63 concrete bits plus infinite unknown more"
     public final long _fidxs; // 63 unique functions per signature
-    public String _name; // Optional debug function name; only for named single function
 
     private TypeFunPtr(byte nil, TypeTuple sig, Type ret, long fidxs) {
         super(TFUNPTR,nil);
@@ -35,30 +34,16 @@ public class TypeFunPtr extends TypeNil {
         _fidxs = fidxs;
     }
 
-    static TypeFunPtr make( byte nil, TypeTuple sig, Type ret, long fidxs ) { return new TypeFunPtr(nil,sig,ret,fidxs).intern(); }
+    public static TypeFunPtr make( byte nil, TypeTuple sig, Type ret, long fidxs ) { return new TypeFunPtr(nil,sig,ret,fidxs).intern(); }
     public static TypeFunPtr make( boolean nil, TypeTuple sig, Type ret ) { return make((byte)(nil ? 3 : 2),sig,ret,-1); }
-    @Override TypeFunPtr makeFrom( byte nil ) { return  nil ==_nil   ? this : make(  nil,_sig,_ret,   _fidxs).setName(_name); }
-    public TypeFunPtr makeFrom( Type ret ) { return     ret ==_ret   ? this : make( _nil,_sig, ret,   _fidxs).setName(_name); }
-    public TypeFunPtr makeFrom( int fidx ) { return make((byte)2, _sig,_ret,1L<<fidx ).setName(_name); }
-
-    // Compute "function indices": FIDX
-    private static final HashMap<TypeTuple,Integer> FIDXS = new HashMap<>();
-    private static int nextFIDX(TypeTuple sig) {
-        Integer i = FIDXS.get(sig);
-        int fidx = i==null ? 0 : i;
-        FIDXS.put(sig,fidx+1);  // Track count per sig
-        assert fidx<64;         // TODO: need a larger FIDX space
-        return fidx;            // Return
-    }
-    public static TypeFunPtr makeFun( TypeTuple sig, Type ret ) {
-        return make((byte)2,sig,ret,1L<<nextFIDX(sig));
-    }
+    @Override TypeFunPtr makeFrom( byte nil ) { return  nil ==_nil   ? this : make(  nil,_sig,_ret,   _fidxs); }
+    public TypeFunPtr makeFrom( Type ret ) { return     ret ==_ret   ? this : make( _nil,_sig, ret,   _fidxs); }
+    public TypeFunPtr makeFrom( int fidx ) { return make((byte)2, _sig,_ret,1L<<fidx ); }
 
     public static TypeFunPtr BOT   = make((byte)3,TypeTuple.BOT,Type.BOTTOM,-1);
     public static TypeFunPtr TEST  = make((byte)2,TypeTuple.TEST,TypeInteger.BOT,1);
     public static TypeFunPtr TEST0 = make((byte)3,TypeTuple.TEST,TypeInteger.BOT,3);
-    public static TypeFunPtr MAIN  = makeFun(TypeTuple.MAIN,Type.BOTTOM).setName("main");
-    public static void gather(ArrayList<Type> ts) { ts.add(TEST); ts.add(TEST0); ts.add(BOT); ts.add(MAIN); }
+    public static void gather(ArrayList<Type> ts) { ts.add(TEST); ts.add(TEST0); ts.add(BOT); }
 
     @Override
     Type xmeet(Type t) {
@@ -93,15 +78,6 @@ public class TypeFunPtr extends TypeNil {
         return _sig == ptr._sig  && _ret == ptr._ret && _fidxs == ptr._fidxs && super.eq(ptr);
     }
 
-    public TypeFunPtr setName(String name) {
-        if( name==null ) return this;
-        assert _fidxs > 0 && Long.bitCount(_fidxs) == 1;
-        // Name can be set to different things, just for debug
-        //assert _name==null || _name.equals(name);
-        _name = name;
-        return this;
-    }
-
     @Override public String str() { return print(new SB()).toString(); }
     @Override public SB  print(SB sb) { return _print(sb,false,true); }
     public SB print(SB sb, boolean n) { return _print(sb,false,n); }
@@ -109,32 +85,20 @@ public class TypeFunPtr extends TypeNil {
     private static SB _print(SB sb, boolean g, Type t) { return g ? t.gprint(sb) : t.print(sb); }
     private SB _print(SB sb, boolean g, boolean n) {
         sb.p(x()).p("{ ");
-        if( n && _name!=null ) sb.p(_name);
-        else {
-            if( _sig._types!=null )
-                for( Type t : _sig._types )
-                    _print(sb,g,t).p(" ");
-            _print(sb.p(g ? "&rarr; " : "-> "),g,_ret).p(" #");
-            if( isHigh() ) sb.p("~");
-            long fidxs = isHigh() ? ~_fidxs : _fidxs;
-            String fidx = fidxs==0 ? ""
-                : Long.bitCount(fidxs) == 1 ? ""+Long.numberOfTrailingZeros(fidxs)
-                : fidxs == -1 ? "ALL"
-                : "b"+Long.toBinaryString(fidxs); // Just some function bits
-            sb.p(fidx);
-        }
-        return sb.p("}").p(q());
+        if( _sig._types!=null )
+            for( Type t : _sig._types )
+                _print(sb,g,t).p(" ");
+        _print(sb.p(g ? "&rarr; " : "-> "),g,_ret).p(" #");
+        if( isHigh() ) sb.p("~");
+        long fidxs = isHigh() ? ~_fidxs : _fidxs;
+        String fidx = fidxs==0 ? ""
+            : Long.bitCount(fidxs) == 1 ? ""+Long.numberOfTrailingZeros(fidxs)
+            : fidxs == -1 ? "ALL"
+            : "b"+Long.toBinaryString(fidxs); // Just some function bits
+        return sb.p(fidx).p("}").p(q());
     }
 
     // Usage: for( long fidxs=fidxs(); fidxs!=0; fidxs=nextFIDX(fidxs) { int fidxs = Long.numberOfTrailingZeros(fidxs); ... }
     public static long nextFIDX(long fidxs) { return fidxs & (fidxs-1); }
 
-    public static void reset() {
-        FIDXS.clear();
-        FIDXS.put(MAIN._sig,1);
-        for( Type t : INTERN.keySet() )
-            if( t instanceof TypeFunPtr tfp && tfp!=MAIN)
-                tfp._name = null;
-    }
-
 }
diff --git a/src/main/java/com/seaofnodes/simple/type/TypeStruct.java b/src/main/java/com/seaofnodes/simple/type/TypeStruct.java
index ee206579..6c5cb8d4 100644
--- a/src/main/java/com/seaofnodes/simple/type/TypeStruct.java
+++ b/src/main/java/com/seaofnodes/simple/type/TypeStruct.java
@@ -49,7 +49,8 @@ public class TypeStruct extends Type {
 
     // Array
     public static TypeStruct makeAry(TypeInteger len, int lenAlias, Type body, int bodyAlias) {
-        assert body instanceof TypeInteger || (body instanceof TypeNil tn && tn.nullable());
+        assert body instanceof TypeInteger || body instanceof TypeFloat || (body instanceof TypeNil tn && tn.nullable());
+        assert len.isa(TypeInteger.U32);
         return make("[" + body.str() + "]",
                     Field.make("#" ,len , lenAlias,true ),
                     Field.make("[]",body,bodyAlias,false));
@@ -61,7 +62,7 @@ public class TypeStruct extends Type {
     public  static final TypeStruct S1  = make("S1", Field.make("a", TypeInteger.BOT, -1, false), Field.make("s2",TypeMemPtr.make((byte)2,S2F),-2, false) );
     private static final TypeStruct S2  = make("S2", Field.make("b", TypeFloat  .F64, -3, false), Field.make("s1",TypeMemPtr.make((byte)2,S1F),-4, false) );
 
-    private static final TypeStruct ARY = makeAry(TypeInteger.BOT,-1,TypeInteger.BOT,-2);
+    private static final TypeStruct ARY = makeAry(TypeInteger.U32,-1,TypeInteger.BOT,-2);
 
     public static void gather(ArrayList<Type> ts) { ts.add(TEST); ts.add(BOT); ts.add(S1); ts.add(S2); ts.add(ARY); }
 
@@ -215,6 +216,11 @@ public class TypeStruct extends Type {
     private int[] offsets() {    // Field byte offsets
         // Compute a layout for a collection of fields
         assert _fields != null; // No forward refs
+
+        // Array layout is different: len,[pad],body...
+        if( isAry() )
+            return _offs = new int[]{ 0, _fields[1]._type.log_size() < 3 ? 4 : 8 };
+
         // Compute a layout
         int[] cnts = new int[4]; // Count of fields at log field size
         for( Field f : _fields )
-- 
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