Chapter 20: Graph Coloring Register Allocationlinear-chapter20

2 files changed, 21 insertions, 4 deletions

diff --git a/src/main/java/com/seaofnodes/simple/node/LoadNode.java b/src/main/java/com/seaofnodes/simple/node/LoadNode.java
index 4004f87f..6c74042b 100644
--- a/src/main/java/com/seaofnodes/simple/node/LoadNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/LoadNode.java
@@ -201,10 +201,10 @@ public class LoadNode extends MemOpNode {
             return new AndNode(null,val,con(ti._max));
         // Signed extension
         int shift = Long.numberOfLeadingZeros(ti._max)-1;
-        if( shift==0 )
-            return val;
         Node shf = con(shift);
-        Node shl = new ShlNode(null,val,shf.keep()).peephole();
-        return new SarNode(null,shl,shf.unkeep());
+        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/test/java/com/seaofnodes/simple/Chapter20Test.java b/src/test/java/com/seaofnodes/simple/Chapter20Test.java
new file mode 100644
index 00000000..48458f95
--- /dev/null
+++ b/src/test/java/com/seaofnodes/simple/Chapter20Test.java
@@ -0,0 +1,17 @@
+package com.seaofnodes.simple;
+
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class Chapter20Test {
+
+    @Test
+    public void testJig() {
+        CodeGen code = new CodeGen("""
+return 0;
+""");
+        code.parse().opto().typeCheck();
+        assertEquals("return 0;", code._stop.toString());
+        assertEquals("0", Eval2.eval(code,  2));
+    }
+}