From d32f97238c903765dec4e9a9f3cbfa5fd12cded6 Mon Sep 17 00:00:00 2001
From: Cliff Click <cliffc@acm.org>
Date: Mon, 10 Aug 2026 11:11:18 -0700
Subject: Chapter 25: Modules, Separate Compilation, and SSA Construction

Co-authored-by: Hsiang-Ying Fu <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: fuhsnn <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: Symious <14933944+symious@users.noreply.github.com>
Co-authored-by: Jun Kawasaki <jun784@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
---
 .../simple/print/SimpleGraphAdapter.java           | 43 +++++++++++++++++-----
 1 file changed, 33 insertions(+), 10 deletions(-)

(limited to 'src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java')

diff --git a/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java b/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
index 8dc6ea47..9ca0ec51 100644
--- a/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
+++ b/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
@@ -2,22 +2,30 @@ package com.seaofnodes.simple.print;
 
 import com.seaofnodes.graph.GraphAdapter;
 import com.seaofnodes.graph.GraphSnapshot.*;
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.*;
 import com.seaofnodes.simple.node.Node;
 import com.seaofnodes.simple.type.TypeMem;
 
-/** Chapter 24's view of the IR; browser, transport and layout are shared. */
+/** Chapter 25's view of the IR, including partially constructed parse-time graphs. */
 public class SimpleGraphAdapter extends GraphAdapter<Node> {
 
+    @Override protected boolean show(Node n) {
+        if( n != CodeGen.CODE.ZERO && n != CodeGen.CODE.XCTRL ) return true;
+        for( int i=0; i<n.nOuts(); i++ )
+            if( n.out(i) != null ) return true;
+        return false; // The parser's keep is not a graph use.
+    }
+
     @Override protected String edgeName(Node n, int i) {
         return n instanceof ScopeNode scope && i < scope._vars.size()
-                ? scope._vars.get(i)._name : null;
+                ? scope.var(i)._name : null;
     }
     @Override protected int edgeJump(Node n, int i) {
         return n instanceof CallEndNode && i>0 && n.in(i) instanceof ReturnNode ret
                 ? ref(ret.fun()) : 0;
     }
-    @Override protected int projectionIndex(Node n) { return n instanceof ProjNode p ? p._idx : n instanceof CProjNode p ? p._idx : -1; }
+    @Override protected int projectionIndex(Node n) { return n instanceof Proj p ? p.idx() : -1; }
 
     @Override protected boolean folding(Node n) {
         if( n instanceof FunNode fun ) return fun.folding();
@@ -32,26 +40,41 @@ public class SimpleGraphAdapter extends GraphAdapter<Node> {
     @Override protected Kind kind(Node n) {
         if( n instanceof StopNode ) return Kind.STOP;
         if( n instanceof ScopeNode ) return Kind.SCOPE;
+        if( n instanceof StartCUNode ) return Kind.UNIT;
         if( n instanceof FunNode ) return Kind.FUN;
-        if( n instanceof StartNode ) return Kind.CTRL;
+        // Start inherits Loop for whole-program analysis, but is not a source loop.
+        if( n instanceof StartNode ) return Kind.START;
         if( n instanceof LoopNode ) return Kind.LOOP;
         if( n instanceof RegionNode ) return Kind.REGION;
         if( n instanceof PhiNode ) return Kind.PHI;
-        return n instanceof CFGNode ? Kind.CTRL : isMem(n) ? Kind.MEM : Kind.DATA;
+        if( n instanceof CFGNode ) return Kind.CTRL;
+        return isMem(n) ? Kind.MEM : Kind.DATA;
     }
 
     @Override protected Role role(Node n, int i) {
-        if( n instanceof ScopeNode || n instanceof ConstantNode || n instanceof CtrlNode || n instanceof XCtrlNode ) return Role.ASSOC;
-        if( n instanceof PhiNode ) return i == 0 ? Role.ASSOC : isMem(n) ? Role.MEM : Role.DATA;
-        if( n instanceof ProjNode || n instanceof CProjNode )
+        if( n instanceof ScopeNode || n instanceof ConstantNode || n instanceof FunPtrNode ||
+            n instanceof CtrlNode || n instanceof XCtrlNode )
+            return Role.ASSOC;
+        if( n instanceof PhiNode )
+            return i == 0 ? Role.ASSOC : isMem(n) ? Role.MEM : Role.DATA;
+        if( n instanceof Proj )
             return n instanceof CFGNode ? Role.CTRL : isMem(n) ? Role.MEM : Role.DATA;
+        // StartCU inherits Region, but slot 0 really connects it to Start.
+        if( n instanceof StartCUNode && i == 0 ) return Role.CTRL;
         if( n instanceof RegionNode && i == 0 ) return Role.ASSOC;
+        // Preserve known slot roles even when an input is not attached/typed yet.
         if( i == 0 || n instanceof RegionNode || n instanceof StopNode ) return Role.CTRL;
-        if( n instanceof MemMergeNode || (i == 1 && (n instanceof MemOpNode || n instanceof ReturnNode || n instanceof CallNode || n instanceof NewNode)) ) return Role.MEM;
+        if( n instanceof MemMergeNode ||
+            (i == 1 && (n instanceof MemOpNode || n instanceof ReturnNode || n instanceof CallNode)) ||
+            (n instanceof EscapeNode && i >= 2) ) return Role.MEM;
         Node def = n.in(i);
+        if( def instanceof CFGNode ) return Role.CTRL;
         if( def != null && isMem(def) ) return Role.MEM;
         return Role.DATA;
     }
 
-    private boolean isMem(Node n) { return n.isMem() || n._type instanceof TypeMem; }
+    private boolean isMem(Node n) {
+        // These Phi subclasses are memory even before their first type computation.
+        return n instanceof MemPhiNode || n instanceof BulkMemPhiNode || n.isMem() || n._type instanceof TypeMem;
+    }
 }
-- 
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