1 files changed, 45 insertions, 0 deletions
diff --git a/docs/2026_REBASE/tools/BackendDump.java b/docs/2026_REBASE/tools/BackendDump.java
new file mode 100644
index 00000000..faac89a4
--- /dev/null
+++ b/docs/2026_REBASE/tools/BackendDump.java
@@ -0,0 +1,45 @@
+import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.node.*;
+import java.nio.file.*;
+import java.util.regex.Pattern;
+
+/** Run from the repo root with Chapter 21's built classes on the classpath. */
+public class BackendDump {
+    static String js(String s) {
+        return "\""+s.replace("\\","\\\\").replace("\"","\\\"")
+            .replace("\r", "").replace("\n","\\n")+"\"";
+    }
+    public static void main(String[] args) throws Exception {
+        Path deck=Path.of("docs/2026_REBASE");
+        String source=Files.readString(deck.resolve("demos/backend.smp"));
+        CodeGen code=new CodeGen(source).parse().opto().typeCheck().loopTree()
+            .instSelect("x86_64_v2","SystemV");
+        String selected=code.toString();
+        // Every row from the whole graph, in printer order. Show concrete Java
+        // classes and every input slot; omit types and redundant use lists.
+        StringBuilder compact=new StringBuilder("id node             inputs\n");
+        var rows=Pattern.compile("(?m)^\\s*(\\d+) ").matcher(selected);
+        int count=0;
+        while(rows.find()) {
+            Node n=code.f(Integer.parseInt(rows.group(1)));
+            String name=n.getClass().getSimpleName();
+            if(n instanceof ParmNode || n instanceof CProjNode) name+=":"+n.label();
+            compact.append(String.format("%2d %-16s",n._nid,name));
+            for(int i=0;i<n.nIns();i++) compact.append(' ').append(n.in(i)==null?"_":n.in(i)._nid);
+            compact.append('\n');
+            count++;
+        }
+        code.GCM().localSched().regAlloc();
+        String assembly=code.asm();
+        code.encode();
+        String encoded=code.asm();
+        Files.writeString(deck.resolve("assets/backend-selected.txt"),selected);
+        Files.writeString(deck.resolve("assets/backend-registers.txt"),assembly);
+        Files.writeString(deck.resolve("assets/backend-encoded.txt"),encoded);
+        Files.writeString(deck.resolve("backend.js"),
+            "/* Generated by tools/BackendDump.java; Chapter 21, x86-64 System V. */\n"+
+            "window.REBASE.backend = {\n  source: "+js(source)+",\n  selected: "+js(compact.toString())+
+            ",\n  assembly: "+js(assembly)+",\n  encoded: "+js(encoded)+"\n};\n");
+        System.out.println("Captured "+count+" selected nodes, allocated assembly, and encoded assembly.");
+    }
+}