Chapter 20: Graph Coloring Register Allocation

Co-authored-by: Tamás Hadházy <85063808+Hels15@users.noreply.github.com>
Co-authored-by: godalming123 <68993177+godalming123@users.noreply.github.com>
Co-authored-by: RobertObkircher <robert.obkircher@gmail.com>

27 files changed, 299 insertions, 114 deletions

diff --git a/src/test/java/com/seaofnodes/simple/BrainFuckTest.java b/src/test/java/com/seaofnodes/simple/BrainFuckTest.java
index 8f09cb3d..c23bb301 100644
--- a/src/test/java/com/seaofnodes/simple/BrainFuckTest.java
+++ b/src/test/java/com/seaofnodes/simple/BrainFuckTest.java
@@ -1,10 +1,11 @@
 package com.seaofnodes.simple;
 
-import com.seaofnodes.simple.evaluator.Evaluator;
+import com.seaofnodes.simple.codegen.CodeGen;
 import java.nio.charset.StandardCharsets;
 import org.junit.Test;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
+import static com.seaofnodes.simple.Main.PORTS;
 
 public class BrainFuckTest {
 
@@ -17,8 +18,7 @@ public class BrainFuckTest {
             encoded.append("program[").append(i).append("] = ").append(value).append(";");
         }
 
-        CodeGen code = new CodeGen(
-                encoded + """
+        String src = encoded + """
 
 int d = 0;
 u8[] !output = new u8[0];
@@ -62,8 +62,10 @@ for( int pc = 0; pc < program#; pc++ ) {
     }
 }
 return output;
-                """);
-        code.parse().opto().typeCheck()/*.instSelect("x86_64_v2", "SystemV")*/.GCM().localSched();
-        assertEquals("Hello World!\n", Eval2.eval(code, 0, 10000));
+""";
+        Chapter20Test.testCPU(src,"x86_64_v2", "SystemV",28,null);
+        Chapter20Test.testCPU(src,"riscv"    , "SystemV",18,null);
+        Chapter20Test.testCPU(src,"arm"      , "SystemV",12,null);
+        //assertEquals("Hello World!\n", Eval2.eval(code, 0, 10000));
     }
 }
diff --git a/src/test/java/com/seaofnodes/simple/Chapter01Test.java b/src/test/java/com/seaofnodes/simple/Chapter01Test.java
index 934eda76..cddbdfcf 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter01Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter01Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.*;
 import com.seaofnodes.simple.type.TypeInteger;
 import org.junit.Test;
diff --git a/src/test/java/com/seaofnodes/simple/Chapter02Test.java b/src/test/java/com/seaofnodes/simple/Chapter02Test.java
index d8607c32..631e1487 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter02Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter02Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.*;
 import com.seaofnodes.simple.type.TypeInteger;
 import org.junit.Test;
diff --git a/src/test/java/com/seaofnodes/simple/Chapter03Test.java b/src/test/java/com/seaofnodes/simple/Chapter03Test.java
index 4f9b2490..c4e4c91e 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter03Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter03Test.java
@@ -1,7 +1,7 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import org.junit.Test;
-
 import static org.junit.Assert.*;
 
 public class Chapter03Test {
diff --git a/src/test/java/com/seaofnodes/simple/Chapter04Test.java b/src/test/java/com/seaofnodes/simple/Chapter04Test.java
index d09b1748..c6199193 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter04Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter04Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.*;
 import com.seaofnodes.simple.type.TypeInteger;
 import org.junit.Test;
diff --git a/src/test/java/com/seaofnodes/simple/Chapter05Test.java b/src/test/java/com/seaofnodes/simple/Chapter05Test.java
index 86ec4136..a584ad5a 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter05Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter05Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.*;
 import org.junit.Test;
 
diff --git a/src/test/java/com/seaofnodes/simple/Chapter06Test.java b/src/test/java/com/seaofnodes/simple/Chapter06Test.java
index 117531f0..24d12921 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter06Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter06Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.*;
 import com.seaofnodes.simple.type.TypeInteger;
 import org.junit.Test;
diff --git a/src/test/java/com/seaofnodes/simple/Chapter07Test.java b/src/test/java/com/seaofnodes/simple/Chapter07Test.java
index 6d6a3ce7..88554323 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter07Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter07Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.*;
 import org.junit.Test;
 
diff --git a/src/test/java/com/seaofnodes/simple/Chapter08Test.java b/src/test/java/com/seaofnodes/simple/Chapter08Test.java
index 350df18b..7e90d484 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter08Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter08Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.*;
 import org.junit.Assert;
 import org.junit.Test;
diff --git a/src/test/java/com/seaofnodes/simple/Chapter09Test.java b/src/test/java/com/seaofnodes/simple/Chapter09Test.java
index 10f4a78b..401f346f 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter09Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter09Test.java
@@ -1,6 +1,6 @@
 package com.seaofnodes.simple;
 
-import com.seaofnodes.simple.evaluator.Evaluator;
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeInteger;
 import org.junit.Assert;
diff --git a/src/test/java/com/seaofnodes/simple/Chapter10Test.java b/src/test/java/com/seaofnodes/simple/Chapter10Test.java
index 02029b3f..1253e4a6 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter10Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter10Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import org.junit.Test;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
diff --git a/src/test/java/com/seaofnodes/simple/Chapter11Test.java b/src/test/java/com/seaofnodes/simple/Chapter11Test.java
index 0b24bd5d..c2b9a86d 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter11Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter11Test.java
@@ -1,8 +1,7 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import org.junit.Test;
-
-
 import static org.junit.Assert.assertEquals;
 
 public class Chapter11Test {
diff --git a/src/test/java/com/seaofnodes/simple/Chapter12Test.java b/src/test/java/com/seaofnodes/simple/Chapter12Test.java
index 21df8205..8069ddaa 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter12Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter12Test.java
@@ -1,8 +1,7 @@
 package com.seaofnodes.simple;
 
-import com.seaofnodes.simple.evaluator.Evaluator;
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.StopNode;
-import org.junit.Ignore;
 import org.junit.Test;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
@@ -43,7 +42,7 @@ while( 1 ) {
 return guess;
 """);
         code.parse().opto();
-        assertEquals("return Phi(Loop,(flt)arg,(((ToFloat/Phi_guess)+Phi_guess)/2.0f));", code.print());
+        assertEquals("return Phi(Loop,(flt)arg,(((ToFloat/Phi_guess)+Phi_guess)*0.5f));", code.print());
         assertEquals("3.0", Eval2.eval(code,  9));
         assertEquals("1.414213562373095", Eval2.eval(code,  2));
     }
diff --git a/src/test/java/com/seaofnodes/simple/Chapter13Test.java b/src/test/java/com/seaofnodes/simple/Chapter13Test.java
index 005a3dd4..977595cb 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter13Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter13Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import org.junit.Test;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
diff --git a/src/test/java/com/seaofnodes/simple/Chapter14Test.java b/src/test/java/com/seaofnodes/simple/Chapter14Test.java
index 17708c37..b83516e3 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter14Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter14Test.java
@@ -1,8 +1,8 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.StopNode;
 import org.junit.Test;
-
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
 
@@ -174,7 +174,7 @@ while(v1) break;
 return v1;
 """);
         code.parse().opto();
-        assertEquals("return Phi(Loop,(((1<<arg)&1)&Shl),0);", code.print());
+        assertEquals("return (Phi(Loop,((1<<arg)&1),0)&Phi(Loop,Shl,4294967295));", code.print());
         assertEquals("1", Eval2.eval(code,  0));
     }
 
diff --git a/src/test/java/com/seaofnodes/simple/Chapter15Test.java b/src/test/java/com/seaofnodes/simple/Chapter15Test.java
index 546eb0e9..7dd0710a 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter15Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter15Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import org.junit.Test;
 import static org.junit.Assert.*;
 
@@ -300,18 +301,20 @@ return is[1];
 
     @Test
     public void testBad3() {
-        CodeGen code = new CodeGen(
-"""
+        CodeGen code = new CodeGen("""
 int[] is = new int[arg];
 return is[1];
 """);
         code.parse().opto();
         assertEquals("return 0;", code.print());
         assertEquals("0", Eval2.eval(code,  4));
-        try { Eval2.eval(code,0); }
-        catch( ArrayIndexOutOfBoundsException e ) { assertEquals("Array index 1 out of bounds for array length 0",e.getMessage()); }
-        try { Eval2.eval(code,-1); }
+        try { Eval2.eval(code,-1); fail(); }
         catch( NegativeArraySizeException e ) { assertEquals("-1",e.getMessage()); }
+        // This test will not pass (i.e., failed range-check) until we have range checks.
+        // Without the range check, the load `is[1]` optimizes against the `new int[]`
+        // and assumes it loads a zero then folds away, and the Eval2 never sees an OOB load.
+        //try { Eval2.eval(code,0); fail(); }
+        //catch( ArrayIndexOutOfBoundsException e ) { assertEquals("Array index 1 out of bounds for array length 0",e.getMessage()); }
     }
 
     @Test
diff --git a/src/test/java/com/seaofnodes/simple/Chapter16Test.java b/src/test/java/com/seaofnodes/simple/Chapter16Test.java
index ad3dc690..930624e5 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter16Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter16Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.evaluator.Evaluator;
 import com.seaofnodes.simple.node.StopNode;
 import org.junit.Test;
diff --git a/src/test/java/com/seaofnodes/simple/Chapter17Test.java b/src/test/java/com/seaofnodes/simple/Chapter17Test.java
index a1d0f8b9..6e43dbc8 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter17Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter17Test.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import org.junit.Test;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
@@ -10,11 +11,9 @@ public class Chapter17Test {
     public void testJig() {
         CodeGen code = new CodeGen(
 """
-int i = 0;
-i=i=1;
-return i;
+return 1;
 """);
-        code.parse().opto();
+        code.parse().opto().typeCheck();
         assertEquals("return 1;", code.print());
         assertEquals("1", Eval2.eval(code,  0));
     }
diff --git a/src/test/java/com/seaofnodes/simple/Chapter18Test.java b/src/test/java/com/seaofnodes/simple/Chapter18Test.java
index db970f60..d0623d12 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter18Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter18Test.java
@@ -1,9 +1,10 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
+import org.junit.Ignore;
 import org.junit.Test;
 import static org.junit.Assert.*;
 import static org.junit.Assert.fail;
-import org.junit.Ignore;
 
 public class Chapter18Test {
 
@@ -77,7 +78,7 @@ var sq = { int x ->
 return sq(arg)+sq(3);
 """);
         code.parse().opto().typeCheck().GCM().localSched();
-        assertEquals("Stop[ return (sq( 3)+sq( arg)); return (Parm_x(sq,int,3,arg)*x); ]", code._stop.toString());
+        assertEquals("Stop[ return (#2+#2); return (Parm_x(sq,int)*x); ]", code._stop.toString());
         assertEquals("13", Eval2.eval(code, 2));
     }
 
@@ -115,7 +116,7 @@ var fcn = arg ? { int x -> x*x; } : { int x -> x+x; };
 return fcn(3);
 """);
         code.parse().opto();
-        assertEquals("Stop[ return Phi(Region,{ int -> int #1},{ int -> int #2})( 3); return (Parm_x($fun,int,3)*x); return (Parm_x($fun,int,3)<<1); ]", code._stop.toString());
+        assertEquals("Stop[ return #2; return (Parm_x($fun1,int,3)*x); return (Parm_x($fun2,int,3)<<1); ]", code._stop.toString());
         assertEquals("6", Eval2.eval(code, 0));
         assertEquals("9", Eval2.eval(code, 1));
     }
@@ -125,7 +126,7 @@ return fcn(3);
     public void testFcn5() {
         CodeGen code = new CodeGen("val fact = { int x -> x <= 1 ? 1 : x*fact(x-1); }; return fact(arg);");
         code.parse().opto().typeCheck();
-        assertEquals("Stop[ return fact( arg); return Phi(Region,1,(Parm_x(fact,int,arg,(x-1))*fact( Sub))); ]", code._stop.toString());
+        assertEquals("Stop[ return #2; return Phi(Region,1,(Parm_x(fact,int,arg,(x-1))*#2)); ]", code._stop.toString());
         assertEquals( "1", Eval2.eval(code, 0));
         assertEquals( "1", Eval2.eval(code, 1));
         assertEquals( "2", Eval2.eval(code, 2));
@@ -175,7 +176,7 @@ for(;;) {
 }
 """);
         code.parse().opto().typeCheck().GCM().localSched();
-        assertEquals("Stop[ return x( Phi(Loop,arg,x( 3))); return Parm_i(x,int,3,Phi_arg); ]", code._stop.toString());
+        assertEquals("Stop[ return #2; return Parm_i(x,int); ]", code._stop.toString());
         assertEquals("3", Eval2.eval(code,  0));
     }
 
@@ -346,7 +347,7 @@ if (i2i) return i2i(arg);
 return f2f(o)(1);
 """);
         code.parse().opto().typeCheck().GCM().localSched();
-        assertEquals("Stop[ return Phi(Region,o( arg),o( 1)); return Parm_i(o,int,arg,1); ]", code._stop.toString());
+        assertEquals("Stop[ return Phi(Region,#2,#2); return Parm_i(o,int); ]", code._stop.toString());
         assertEquals("1", Eval2.eval(code,  2));
     }
 
diff --git a/src/test/java/com/seaofnodes/simple/Chapter19Test.java b/src/test/java/com/seaofnodes/simple/Chapter19Test.java
index 990c4c32..bb7e8716 100644
--- a/src/test/java/com/seaofnodes/simple/Chapter19Test.java
+++ b/src/test/java/com/seaofnodes/simple/Chapter19Test.java
@@ -1,9 +1,11 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
+import org.junit.Ignore;
 import org.junit.Test;
+import static com.seaofnodes.simple.Main.PORTS;
 import static org.junit.Assert.*;
 import static org.junit.Assert.fail;
-import org.junit.Ignore;
 
 public class Chapter19Test {
 
@@ -55,107 +57,107 @@ val _hashCodeString = { String self ->
 String !s = new String { cs = new u8[17]; };
 s.cs[0] =  67; // C
 s.cs[1] = 108; // l
-hashCode(s);""");
+hashCode(s)+hashCode(s);""");
         code.parse().opto().typeCheck().GCM().localSched();
-        assertEquals("Stop[ return Phi(Region,123456789,Phi(Loop,0,(.[]+((Phi_hash<<5)-Phi_hash)))); return Phi(Region,1,0,0,1); ]", code._stop.toString());
-        assertEquals("-2449306563677080489", Eval2.eval(code,  2));
+        assertEquals("Stop[ return (#2+#2); return Phi(Region,1,0,0,1); return Phi(Region,._hashCode,Phi(Region,123456789,Phi(Loop,0,(.[]+((Phi_hash<<5)-Phi_hash))))); ]", code._stop.toString());
+        assertEquals("-4898613127354160978", Eval2.eval(code,  2));
     }
 
     @Test
     public void testBasic0() {
-        CodeGen code = new CodeGen("return 0;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return 0;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return 0;", code._stop.toString());
     }
 
     @Test
     public void testBasic1() {
-        CodeGen code = new CodeGen("return arg+1;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg+1;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (inc,arg);", code._stop.toString());
     }
 
     @Test
     public void testBasic2() {
-        CodeGen code = new CodeGen("return -17;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return -17;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return -17;", code._stop.toString());
     }
 
 
     @Test
     public void testBasic3() {
-        CodeGen code = new CodeGen("return arg==1;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg==1;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (set==,(cmp,arg));", code._stop.toString());
     }
 
     @Test
     public void testBasic4() {
-        CodeGen code = new CodeGen("return arg<<1;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg<<1;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (shli,arg);", code._stop.toString());
     }
 
     @Test
     public void testBasic5() {
-        CodeGen code = new CodeGen("return arg >> 1;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg >> 1;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (sari,arg);", code._stop.toString());
     }
 
     @Test
     public void testBasic6() {
-        CodeGen code = new CodeGen("return arg >>> 1;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg >>> 1;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (shri,arg);", code._stop.toString());
     }
 
     @Test
     public void testBasic7() {
-        CodeGen code = new CodeGen("return arg / 2;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg / 2;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (div,arg,2);", code._stop.toString());
     }
 
     @Test
     public void testBasic8() {
-        CodeGen code = new CodeGen("return arg * 6;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg * 6;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (muli,arg);", code._stop.toString());
     }
 
     @Test
     public void testBasic9() {
-        CodeGen code = new CodeGen("return arg & 2;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg & 2;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (andi,arg);", code._stop.toString());
     }
 
     @Test
     public void testBasic10() {
-        CodeGen code = new CodeGen("return arg | 2;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg | 2;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (ori,arg);", code._stop.toString());
     }
 
     @Test
     public void testBasic11() {
-        CodeGen code = new CodeGen("return arg ^ 2;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg ^ 2;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (xori,arg);", code._stop.toString());
     }
 
     @Test
     public void testBasic12() {
-        CodeGen code = new CodeGen("return arg + 2.0;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg + 2.0;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (addf,(i2f8,arg),2.0f);", code._stop.toString());
     }
 
     @Test
     public void testBasic13() {
-        CodeGen code = new CodeGen("return arg - 2.0;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg - 2.0;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (subf,(i2f8,arg),2.0f);", code._stop.toString());
     }
 
     @Test
     public void testBasic14() {
-        CodeGen code = new CodeGen("return arg * 2.0;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        CodeGen code = new CodeGen("return arg * 2.0;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (mulf,(i2f8,arg),2.0f);", code._stop.toString());
     }
 
     @Test
     public void testBasic15() {
-        CodeGen code = new CodeGen("return arg / 2.0;").parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
-        assertEquals("return (divf,(i2f8,arg),2.0f);", code._stop.toString());
+        CodeGen code = new CodeGen("return arg / 2.0;").parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
+        assertEquals("return (mulf,(i2f8,arg),0.5f);", code._stop.toString());
     }
 
     @Test
@@ -164,7 +166,7 @@ hashCode(s);""");
 """
 int arg1 =  arg + 1;
 return arg1 / arg;""");
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (div,(inc,arg),arg);", code._stop.toString());
     }
 
@@ -175,50 +177,17 @@ return arg1 / arg;""");
 int arg1 =  arg + 1;
 return arg1 * arg;
 """);
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (mul,(inc,arg),arg);", code._stop.toString());
     }
 
     @Test
-    public void testBasic18() {
-        CodeGen code = new CodeGen(
-                """
-                int arg1 =  arg + 1;
-                return arg1 << arg;
-                """);
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
-        assertEquals("return (shl,(inc,arg),arg);", code._stop.toString());
-    }
-
-    @Test
-    public void testBasic19() {
-        CodeGen code = new CodeGen(
-                """
-                int arg1 =  arg + 1;
-                return arg1 >> arg;
-                """);
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
-        assertEquals("return (sar,(inc,arg),arg);", code._stop.toString());
-    }
-
-    @Test
-    public void testBasic20() {
-        CodeGen code = new CodeGen(
-                """
-                int arg1 =  arg + 1;
-                return arg1 >>> arg;
-                """);
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
-        assertEquals("return (shr,(inc,arg),arg);", code._stop.toString());
-    }
-
-    @Test
     public void testToFloat() {
         CodeGen code = new CodeGen("""
                 int a = arg;
                 return a + 2.0;
                 """
-        ).parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        ).parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (addf,(i2f8,arg),2.0f);", code._stop.toString());
     }
 
@@ -233,7 +202,7 @@ else {
     a = arg-3;
 }
 return a;""");
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return Phi(Region,(addi,arg),(addi,arg));", code.print());
     }
 
@@ -248,7 +217,7 @@ if( arg==1 )
 else
     a=b+1;
 return a+b;""");
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (add,(add,Phi(Region,(shli,arg),arg),arg),Phi(Region,4,5));", code.print());
     }
 
@@ -260,7 +229,7 @@ int sum=0;
 for( int i=0; i<arg; i++ )
     sum += i;
 return sum;""");
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return Phi(Loop,0,(add,Phi_sum,Phi(Loop,0,(inc,Phi_i))));", code.print());
     }
 
@@ -270,42 +239,42 @@ return sum;""");
 """
 struct S { int a; S? c; };
 return new S;""");
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return S;", code.print());
     }
 
     @Test
     public void testLea1() {
         CodeGen code = new CodeGen("int x = arg/3; return arg+x+7;");
-        code.parse().opto().typeCheck().instSelect("x86_64_v2",  "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2",  "SystemV").GCM().localSched();
         assertEquals("return (lea,arg,(div,arg,3));", code.print());
     }
 
     @Test
     public void testLea2() {
         CodeGen code = new CodeGen("int x = arg/3; return arg+x*4+7;");
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return (lea,arg,(div,arg,3));", code.print());
     }
 
     @Test
     public void testLea3() {
         CodeGen code = new CodeGen("int x = arg/3; return x*4+arg;");
-        code.parse().opto().typeCheck().instSelect("x86_64_v2",  "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2",  "SystemV").GCM().localSched();
         assertEquals("return (lea,arg,(div,arg,3));", code.print());
     }
 
     @Test
     public void testAlloc2() {
         CodeGen code = new CodeGen("int[] !xs = new int[3]; xs[arg]=1; return xs[arg&1];");
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return .[];", code.print());
     }
 
     @Test
     public void testAlloc3() {
         CodeGen code = new CodeGen("int[] !xs = new int[3]; xs[arg]=1; return xs[arg&1]+3;");
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return .[];", code.print());
     }
 
@@ -322,7 +291,7 @@ for( int i=0; i<ary#-1; i++ )
     ary[i+1] += ary[i];
 return ary[1] * 1000 + ary[3]; // 1 * 1000 + 6
 """);
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return .[];", code.print());
     }
 
@@ -337,7 +306,7 @@ for( int i=0; i<A#; i++ )
 for( int i=0; i<A#; i++ )
     B[i] += A[i];
 """);
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return 0;", code.print());
     }
 
@@ -350,7 +319,7 @@ for( int i=0; i<A#; i++ )
     A[i]++;
 return A[1];
 """);
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return .[];", code.print());
     }
 
@@ -370,8 +339,8 @@ val sqrt = { flt x ->
 flt farg = arg;
 return sqrt(farg);
 """);
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
-        assertEquals("return Phi(Loop,(i2f8,arg),(divf,(addf,(divf,i2f8,Phi_guess),Phi_guess),2.0f));", code.print());
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
+        assertEquals("return Phi(Loop,(i2f8,arg),(mulf,(addf,(divf,i2f8,Phi_guess),Phi_guess),0.5f));", code.print());
     };
 
 
@@ -401,7 +370,7 @@ for( int j=0; j<nprimes; j++ )
     rez[j] = primes[j];
 return rez;
 """);
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
         assertEquals("return [int];", code.print());
         //assertEquals("int[ 2,3,5,7,11,13,17,19]",Eval2.eval(code, 20));
     }
@@ -414,8 +383,8 @@ return rez;
 val fcn = arg ? { int x -> x*x; } : { int x -> x+x; };
 return fcn(2)*10 + fcn(3);
 """);
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
-        assertEquals("Stop[ return (add,Phi(Region,{ int -> int #1},{ int -> int #2})( 3),(muli,Phi_( 2))); return (mul,Parm_x($fun,int,3,2),x); return (shli,Parm_x($fun,int,3,2)); ]", code.print());
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
+        assertEquals("Stop[ return (add,#2,(muli,#2)); return (mul,Parm_x($fun1,int),x); return (shli,Parm_x($fun2,int)); ]", code.print());
     }
 
     @Test
@@ -425,7 +394,7 @@ return fcn(2)*10 + fcn(3);
 val sq = { int x -> x*x; };
 return sq(arg) + sq(3);
 """);
-        code.parse().opto().typeCheck().instSelect("x86_64_v2", "SystemV").GCM().localSched();
-        assertEquals("Stop[ return (add,sq(),sq()); return (mul,Parm_x(sq,int,3,arg),x); ]", code.print());
+        code.parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2", "SystemV").GCM().localSched();
+        assertEquals("Stop[ return (add,#2,#2); return (mul,Parm_x(sq,int),x); ]", code.print());
     }
 }
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..008f5e0c
--- /dev/null
+++ b/src/test/java/com/seaofnodes/simple/Chapter20Test.java
@@ -0,0 +1,196 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.print.ASMPrinter;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+import static com.seaofnodes.simple.Main.PORTS;
+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));
+    }
+
+    static void testCPU( String src, String cpu, String os, int spills, String stop ) {
+        CodeGen code = new CodeGen(src);
+        code.parse().opto().typeCheck().instSelect(PORTS,cpu,os).GCM().localSched().regAlloc().encode();
+        int delta = spills>>3;
+        if( delta==0 ) delta = 1;
+        assertEquals("Expect spills:",spills,code._regAlloc._spillScaled,delta);
+        if( stop != null )
+            assertEquals(stop, code._stop.toString());
+    }
+
+    private static void testAllCPUs( String src, int spills, String stop ) {
+        testCPU(src,"x86_64_v2", "SystemV",spills,stop);
+        testCPU(src,"riscv"    , "SystemV",spills,stop);
+        testCPU(src,"arm"      , "SystemV",spills,stop);
+    }
+
+    @Test public void testAlloc0() {
+        testAllCPUs("return new u8[arg];", 1, "return [u8];");
+    }
+
+    @Test public void testBasic1() {
+        String src = "return arg | 2;";
+        testCPU(src,"x86_64_v2", "SystemV",1,"return (ori,mov(arg));");
+        testCPU(src,"riscv"    , "SystemV",0,"return ( arg | #2 );");
+        testCPU(src,"arm"      , "SystemV",0,"return (ori,arg);");
+    }
+
+    @Test
+    public void testNewtonInteger() {
+        String src =
+"""
+// Newtons approximation to the square root
+val sqrt = { int x ->
+    int guess = x;
+    while( 1 ) {
+        int next = (x/guess + guess)/2;
+        if( next == guess ) return guess;
+        guess = next;
+    }
+};
+return sqrt(arg) + sqrt(arg+2);
+""";
+        testCPU(src,"x86_64_v2", "SystemV",26,null);
+        testCPU(src,"riscv"    , "SystemV",19,null);
+        testCPU(src,"arm"      , "SystemV",26,null);
+    }
+
+    @Test
+    public void testNewtonFloat() {
+        String src =
+"""
+// Newtons approximation to the square root
+val sqrt = { flt x ->
+    flt guess = x;
+    while( 1 ) {
+        flt next = (x/guess + guess)/2;
+        if( next == guess ) return guess;
+        guess = next;
+    }
+};
+flt farg = arg;
+return sqrt(farg) + sqrt(farg+2.0);
+""";
+        testCPU(src,"x86_64_v2", "SystemV",25,null);
+        testCPU(src,"riscv"    , "SystemV",21,null);
+        testCPU(src,"arm"      , "SystemV",18,null);
+    }
+
+    @Test
+    public void testAlloc2() {
+        String src = "int[] !xs = new int[3]; xs[arg]=1; return xs[arg&1];";
+        testAllCPUs(src,1,"return .[];");
+    }
+
+    @Test
+    public void testArray1() {
+        String src =
+"""
+int[] !ary = new int[arg];
+// Fill [0,1,2,3,4,...]
+for( int i=0; i<ary#; i++ )
+    ary[i] = i;
+// Fill [0,1,3,6,10,...]
+for( int i=0; i<ary#-1; i++ )
+    ary[i+1] += ary[i];
+return ary[1] * 1000 + ary[3]; // 1 * 1000 + 6
+""";
+        testCPU(src,"x86_64_v2", "SystemV",3,"return .[];");
+        testCPU(src,"riscv"    , "SystemV",1,"return (add,.[],(mul,.[],1000));");
+        testCPU(src,"arm"      , "SystemV",1,"return (add,.[],(muli,.[]));");
+    }
+
+    @Test
+    public void testString() {
+        String src = """
+struct String {
+    u8[] cs;
+    int _hashCode;
+};
+
+val equals = { String self, String s ->
+    if( self == s ) return true;
+    if( self.cs# != s.cs# ) return false;
+    for( int i=0; i< self.cs#; i++ )
+        if( self.cs[i] != s.cs[i] )
+            return false;
+    return true;
+};
+
+val hashCode = { String self ->
+    self._hashCode
+    ?  self._hashCode
+    : (self._hashCode = _hashCodeString(self));
+};
+
+val _hashCodeString = { String self ->
+    int hash=0;
+    if( self.cs ) {
+        for( int i=0; i< self.cs#; i++ )
+            hash = hash*31 + self.cs[i];
+    }
+    if( !hash ) hash = 123456789;
+    return hash;
+};
+
+String !s = new String { cs = new u8[17]; };
+s.cs[0] =  67; // C
+s.cs[1] = 108; // l
+hashCode(s);
+""";
+        testCPU(src,"x86_64_v2", "SystemV",18,null);
+        testCPU(src,"riscv"    , "SystemV", 3,null);
+        testCPU(src,"arm"      , "SystemV", 3,null);
+    }
+
+    @Test
+    public void testCast() {
+        String src = "struct Bar { int x; }; var b = arg ? new Bar;  return b ? b.x++ + b.x++ : -1;";
+        testAllCPUs(src,0,null);
+    }
+
+    @Test
+    public void testFltArg() {
+        String src = "return {int i, flt f, int j->return i+f+j;};";
+        testAllCPUs(src,0,null);
+    }
+
+    @Test
+    public void testFlags1() {
+        String src = """
+bool b1 = arg == 1;
+bool b2 = arg == 2;
+if (b2) if (b1) return 1;
+if (b1) return 2;
+return 0;
+""";
+        testCPU(src,"x86_64_v2", "SystemV",0,"return Phi(Region,1,2,0);");
+        testCPU(src,"riscv"    , "SystemV",0,"return Phi(Region,1,2,0);");
+        testCPU(src,"arm"      , "SystemV",0,"return Phi(Region,1,2,0);");
+    }
+
+    @Test
+    public void testFlags2() {
+        String src = """
+bool b1 = arg == 1;
+while (arg > 0) {
+    arg--;
+    if (b1) arg--;
+}
+return arg;
+""";
+        testCPU(src,"x86_64_v2", "SystemV",3,null);
+        testCPU(src,"riscv"    , "SystemV",2,null);
+        testCPU(src,"arm"      , "SystemV",2,null);
+    }
+}
diff --git a/src/test/java/com/seaofnodes/simple/Eval2.java b/src/test/java/com/seaofnodes/simple/Eval2.java
index 6ae8427c..ecea97dd 100644
--- a/src/test/java/com/seaofnodes/simple/Eval2.java
+++ b/src/test/java/com/seaofnodes/simple/Eval2.java
@@ -1,7 +1,9 @@
 package com.seaofnodes.simple;
 
-import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.print.IRPrinter;
+import com.seaofnodes.simple.type.*;
 import java.util.*;
 
 public abstract class Eval2 {
diff --git a/src/test/java/com/seaofnodes/simple/Main.java b/src/test/java/com/seaofnodes/simple/Main.java
index 523bd306..f3a6784c 100644
--- a/src/test/java/com/seaofnodes/simple/Main.java
+++ b/src/test/java/com/seaofnodes/simple/Main.java
@@ -1,9 +1,11 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import java.nio.file.Files;
 import java.nio.file.Path;
 
 public class Main {
+    public static final String PORTS = "com.seaofnodes.simple.node.cpus";
     // Compile and run a simple program
     public static void main( String[] args ) throws Exception {
         // First arg is file, 2nd+ args are program args
diff --git a/src/test/java/com/seaofnodes/simple/MergeSortTest.java b/src/test/java/com/seaofnodes/simple/MergeSortTest.java
index d48449d5..c83fe089 100644
--- a/src/test/java/com/seaofnodes/simple/MergeSortTest.java
+++ b/src/test/java/com/seaofnodes/simple/MergeSortTest.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import org.junit.Test;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
@@ -8,7 +9,7 @@ public class MergeSortTest {
 
     @Test
     public void testMergeSort() {
-        CodeGen code = new CodeGen(
+        String src =
 """
 // based on the top-down version from https://en.wikipedia.org/wiki/Merge_sort
 
@@ -56,10 +57,11 @@ for (int i = 0; i < a#; i++)
 merge_sort(a, b, a#);
 
 return a;
-""");
-        code.parse().opto();
-        assertEquals("Stop[ return [int]; return 0; ]", code._stop.toString());
-        assertEquals("int[ 1,2,3,4,5,6,7,8,9,10,11]", Eval2.eval(code, 11));
+""";
+        Chapter20Test.testCPU(src,"x86_64_v2", "SystemV",46,"Stop[ return mov(mov([int])); return 0; ]");
+        Chapter20Test.testCPU(src,"riscv"    , "SystemV",36,"Stop[ return mov(mov([int])); return 0; ]");
+        Chapter20Test.testCPU(src,"arm"      , "SystemV",37,"Stop[ return mov(mov([int])); return 0; ]");
+//assertEquals("int[ 1,2,3,4,5,6,7,8,9,10,11]", Eval2.eval(code, 11));
     }
 
 }
diff --git a/src/test/java/com/seaofnodes/simple/SchedulerTest.java b/src/test/java/com/seaofnodes/simple/SchedulerTest.java
index d50c302a..ca29bf84 100644
--- a/src/test/java/com/seaofnodes/simple/SchedulerTest.java
+++ b/src/test/java/com/seaofnodes/simple/SchedulerTest.java
@@ -1,5 +1,6 @@
 package com.seaofnodes.simple;
 
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.evaluator.Evaluator;
 import com.seaofnodes.simple.node.StopNode;
 import org.junit.Assert;
diff --git a/src/test/java/com/seaofnodes/simple/fuzzer/Fuzzer.java b/src/test/java/com/seaofnodes/simple/fuzzer/Fuzzer.java
index f7e0c4ad..30a548ad 100644
--- a/src/test/java/com/seaofnodes/simple/fuzzer/Fuzzer.java
+++ b/src/test/java/com/seaofnodes/simple/fuzzer/Fuzzer.java
@@ -2,7 +2,7 @@ package com.seaofnodes.simple.fuzzer;
 
 import com.seaofnodes.simple.Parser;
 import com.seaofnodes.simple.Eval2;
-import com.seaofnodes.simple.CodeGen;
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.Node;
 import java.util.ArrayList;
 import java.util.Objects;
diff --git a/src/test/java/com/seaofnodes/simple/fuzzer/FuzzerUtils.java b/src/test/java/com/seaofnodes/simple/fuzzer/FuzzerUtils.java
index 0781ad67..669a1e6a 100644
--- a/src/test/java/com/seaofnodes/simple/fuzzer/FuzzerUtils.java
+++ b/src/test/java/com/seaofnodes/simple/fuzzer/FuzzerUtils.java
@@ -1,7 +1,7 @@
 package com.seaofnodes.simple.fuzzer;
 
-import com.seaofnodes.simple.CodeGen;
 import com.seaofnodes.simple.IterPeeps;
+import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.Node;
 import com.seaofnodes.simple.node.StopNode;
 import com.seaofnodes.simple.type.TypeInteger;