Chapter 25: Modules, Separate Compilation, and SSA Constructionlinear

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>

1 files changed, 21 insertions, 17 deletions

diff --git a/src/main/java/com/seaofnodes/simple/node/LoopNode.java b/src/main/java/com/seaofnodes/simple/node/LoopNode.java
index 1d493db7..df686bcf 100644
--- a/src/main/java/com/seaofnodes/simple/node/LoopNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/LoopNode.java
@@ -3,23 +3,22 @@ package com.seaofnodes.simple.node;
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.type.Type;
-import com.seaofnodes.simple.type.TypeInteger;
 import com.seaofnodes.simple.type.TypeMem;
-import com.seaofnodes.simple.util.Utils;
-import java.util.BitSet;
-import java.util.HashSet;
+import com.seaofnodes.simple.util.BAOS;
+
+import java.util.HashMap;
+import java.util.IdentityHashMap;
 
 public class LoopNode extends RegionNode {
-    public LoopNode( Parser.Lexer loc, Node entry ) { super(loc,null,entry,null); }
+    public LoopNode( Parser.Lexer loc, Node xctrl, Node entry ) { super(loc,xctrl,entry,null); }
     public LoopNode( LoopNode loop ) { super(loop); }
+    @Override public Tag serialTag() { return Tag.Loop; }
+    public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) { }
 
     public CFGNode entry() { return cfg(1); }
     public CFGNode back () { return cfg(2); }
 
     @Override
-    public String label() { return "Loop"; }
-
-    @Override
     public Type compute() {
         if( inProgress() ) return Type.CONTROL;
         return entry()._type;
@@ -46,7 +45,7 @@ public class LoopNode extends RegionNode {
             x = x.idom();
         }
         // Found a no-exit loop.  Insert an exit
-        NeverNode iff = (NeverNode)new NeverNode(back()).peephole(); // Ideal never-branch
+        NeverNode iff = (NeverNode)new NeverNode(1.2f,back()).peephole(); // Ideal never-branch
         CProjNode t = new CProjNode(iff,0,"True" ).init();
         CProjNode f = new CProjNode(iff,1,"False").init();
         setDef(2,t);            // True continues loop, False (never) exits loop
@@ -56,12 +55,13 @@ public class LoopNode extends RegionNode {
 
         // Now fold control into the exit.  Might have 1 valid exit, or an
         // XCtrl or a bunch of prior NeverNode exits.
-        Node top = new ConstantNode(Type.TOP).peephole();
-        MemMergeNode memout = new MemMergeNode(new ConstantNode(TypeMem.BOT).peephole());
-        memout.setDef(0,f);
+        Node top = ConstantNode.make(Type.TOP).peephole();
+        Node memout = new MemMergeNode();
+        memout.addDef(f); // placeholder for control
+        memout.addDef(top);
         for( Node u : _outputs )
-            if( u instanceof BulkMemPhiNode ) memout.setDef(1,u);
-            else if( u instanceof MemPhiNode phi ) memout.alias(phi._alias,phi);
+            if( u instanceof PhiNode phi && phi._type.isa(TypeMem.BOT) )
+                memout.addDef(phi);
         memout.init();
 
         Node ctrl = ret.ctrl(), mem = ret.mem(), expr = ret.expr();
@@ -73,7 +73,7 @@ public class LoopNode extends RegionNode {
                 // Nope, insert an aligned exit layer
                 RegionNode r = new RegionNode(_loc,null,ctrl).init();
                 ctrl = r;  r._ltree = fun._ltree;
-                mem  = new BulkMemPhiNode(ScopeNode.MEM0,r,mem).init();
+                mem  = new BulkMemPhiNode(r,mem).init();
                 expr = new PhiNode(r,expr).init();
             }
             // Append new Never exit
@@ -88,8 +88,12 @@ public class LoopNode extends RegionNode {
         ret.setDef(0,ctrl.unkeep());
         ret.setDef(1,mem .unkeep());
         ret.setDef(2,expr.unkeep());
-        ret._type = null; // This may LIFT the Return type, from [XCtrl,mem,expr] to [Ctrl,mem,expr]
-        ret.setType(ret.compute());
+        // Force sane types to exit; might locally break monotonicity
+        ret.init();
+        ret.out(0).init();
+        stop.init();
+        CodeGen.CODE.add(CodeGen.CODE._start);
+        CodeGen.CODE.add(mem);
 
         return fun;
     }