Move insertAfterAndReplace to RA

Fix Split printing

3 files changed, 27 insertions, 25 deletions

diff --git a/chapter21/src/main/java/com/seaofnodes/simple/codegen/RegAlloc.java b/chapter21/src/main/java/com/seaofnodes/simple/codegen/RegAlloc.java
index f595bf74..1fe5591b 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/codegen/RegAlloc.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/codegen/RegAlloc.java
@@ -251,7 +251,7 @@ public class RegAlloc {
             //   alloc
             //     V2/rax - kills prior RAX
             //   st4 [V1],len - No good, must split around
-            makeSplit("def/empty1",round,lrg).insertAfterAndReplace((Node)lrg._machDef, this, false/*true*/);
+            insertAfterAndReplace( makeSplit("def/empty1",round,lrg), (Node)lrg._machDef, false/*true*/);
         // Split just before use
         if( lrg._1regUseCnt==1 || (lrg._1regDefCnt==1 && ((Node)lrg._machDef).nOuts()==1) )
             insertBefore((Node)lrg._machUse,lrg._uidx,"use/empty1",round,lrg);
@@ -341,7 +341,7 @@ public class RegAlloc {
             // TODO: split before all inputs (except the last; at least 1 split here must be extra)
             if( def instanceof PhiNode phi && !(def instanceof ParmNode) ) {
                 SplitNode split = makeSplit("def/self",round,lrg);
-                split.insertAfterAndReplace(def,this,false);
+                insertAfterAndReplace(split,def,false);
                 if( split.nOuts()==0 )
                     split.kill();
                 insertBefore(phi,1,"use/self/phi",round,lrg);
@@ -398,7 +398,7 @@ public class RegAlloc {
                     // Single user is already a split adjacent
                     !(n.nOuts()==1 && n.out(0) instanceof SplitNode split && sameBlockNoClobber(split) ) )
                     // Split after def in min loop nest
-                    makeSplit("def/loop",round,lrg).insertAfterAndReplace(n,this,true);
+                    insertAfterAndReplace( makeSplit("def/loop",round,lrg), n,true);
             }
 
             // PhiNodes check all CFG inputs
@@ -488,6 +488,24 @@ public class RegAlloc {
         insertBefore(n,i,kind,round,lrg,true);
     }
 
+    // Replace uses of `def` with `split`, and insert `split` immediately after
+    // `def` in the basic block.
+    public void insertAfterAndReplace( Node split, Node def, boolean must ) {
+        split.insertAfter(def);
+        if( split.nIns()>1 ) split.setDef(1,def);
+        for( int j=def.nOuts()-1; j>=0; j-- ) {
+            Node use = def.out(j);
+            if( use==split ) continue; // Skip self
+            // Can we avoid a split of a split?  'this' split is used by
+            // another split in the same block.
+            if( !must && use instanceof SplitNode split2 && sameBlockNoClobber(split2) )
+                continue;
+            int idx = use._inputs.find(def);
+            use.setDefOrdered(idx,split);
+            if( j < def.nOuts() ) j++;
+        }
+    }
+
     private Node makeSplit( Node def, String kind, byte round, LRG lrg ) {
         Node split = def instanceof MachNode mach && mach.isClone()
             ? mach.copy()
@@ -559,6 +577,7 @@ public class RegAlloc {
         return true;
     }
 
+
     public boolean sameBlockNoClobber( SplitNode split ) {
         Node def = split.in(1);
         CFGNode cfg = def.cfg0();
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/Node.java b/chapter21/src/main/java/com/seaofnodes/simple/node/Node.java
index 28f70fce..44c9d7cf 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/Node.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/Node.java
@@ -10,7 +10,6 @@ import com.seaofnodes.simple.type.TypeInteger;
 import java.util.*;
 import java.util.function.Function;
 import static com.seaofnodes.simple.codegen.CodeGen.CODE;
-import com.seaofnodes.simple.codegen.RegAlloc;
 
 /**
  * All Nodes in the Sea of Nodes IR inherit from the Node class.
@@ -304,7 +303,7 @@ public abstract class Node {
     }
 
     // insert `this` immediately after `def` in the same basic block.
-    public CFGNode insertAfter( Node def ) {
+    public void insertAfter( Node def ) {
         CFGNode cfg = def.cfg0();
         int i = cfg._outputs.find(def)+1;
         if( cfg instanceof CallEndNode ) {
@@ -317,25 +316,6 @@ public abstract class Node {
         while( cfg.out(i) instanceof PhiNode || cfg.out(i) instanceof CalleeSaveNode )  i++;
         cfg._outputs.insert(this,i);
         _inputs.set(0,cfg);
-        return cfg;
-    }
-
-    // Replace uses of `def` with `this`, and insert `this` immediately after
-    // `def` in the basic block.
-    public void insertAfterAndReplace( Node def, RegAlloc r, boolean must ) {
-        CFGNode cfg = insertAfter(def);
-        for( int j=def.nOuts()-1; j>=0; j-- ) {
-            // Can we avoid a split of a split?  'this' split is used by
-            // another split in the same block.
-            if( !must && def.out(j) instanceof SplitNode split && r.sameBlockNoClobber(split) )
-                continue;
-            Node use = def._outputs.del(j);
-            use.unlock();
-            int idx = use._inputs.find(def);
-            use._inputs.set(idx,this);
-            addUse(use);
-        }
-        if( nIns()>1 ) setDef(1,def);
     }
 
     // Insert this in front of use.in(uidx) with this, and insert this
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/SplitNode.java b/chapter21/src/main/java/com/seaofnodes/simple/node/SplitNode.java
index 22cb9bb9..3a1ed011 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/SplitNode.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/SplitNode.java
@@ -11,7 +11,10 @@ public abstract class SplitNode extends MachConcreteNode {
     public SplitNode(String kind, byte round, Node[] nodes) { super(nodes); _kind = kind; _round = round; }
     @Override public String op() { return "mov"; }
     @Override public StringBuilder _print1(StringBuilder sb, BitSet visited) {
-        return in(1)._print0(sb.append("mov("),visited).append(")");
+        sb.append("mov(");
+        if( in(1) == null ) sb.append("---");
+        else in(1)._print0(sb,visited);
+        return sb.append(")");
     }
     @Override public Type compute() { return in(0)._type; }
     @Override public Node idealize() { return null; }