From e481e3d215882faa82b19f29cfde5746d4e51863 Mon Sep 17 00:00:00 2001
From: Cliff Click <cliffc@acm.org>
Date: Wed, 28 Oct 2026 12:26:28 -0700
Subject: Backport Opto speedups and Minus fix

---
 .../java/com/seaofnodes/simple/Chapter20Test.java  |  2 +-
 .../java/com/seaofnodes/simple/MinusNodeTest.java  | 73 ++++++++++++++++++++++
 2 files changed, 74 insertions(+), 1 deletion(-)
 create mode 100644 chapter27/src/test/java/com/seaofnodes/simple/MinusNodeTest.java

(limited to 'chapter27/src/test/java/com/seaofnodes')

diff --git a/chapter27/src/test/java/com/seaofnodes/simple/Chapter20Test.java b/chapter27/src/test/java/com/seaofnodes/simple/Chapter20Test.java
index c5e4c583..2db10f8f 100644
--- a/chapter27/src/test/java/com/seaofnodes/simple/Chapter20Test.java
+++ b/chapter27/src/test/java/com/seaofnodes/simple/Chapter20Test.java
@@ -243,7 +243,7 @@ s.cs[0] =  67; // C
 s.cs[1] = 108; // l
 hashCode(s);
 """;
-        testTarget(src,"x86_64_v2", "SystemV",9,null);
+        testTarget(src,"x86_64_v2", "SystemV",0,null);
         testTarget(src,"riscv"    , "SystemV",1,null);
         testTarget(src,"arm"      , "SystemV",1,null);
     }
diff --git a/chapter27/src/test/java/com/seaofnodes/simple/MinusNodeTest.java b/chapter27/src/test/java/com/seaofnodes/simple/MinusNodeTest.java
new file mode 100644
index 00000000..497546df
--- /dev/null
+++ b/chapter27/src/test/java/com/seaofnodes/simple/MinusNodeTest.java
@@ -0,0 +1,73 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.node.ConstantNode;
+import com.seaofnodes.simple.node.MinusNode;
+import com.seaofnodes.simple.node.Node;
+import com.seaofnodes.simple.type.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class MinusNodeTest {
+    @Test public void testMonotoneCompute() {
+        CodeGen code = new CodeGen("return 0;");
+        // Type.gather also loads cached fixtures which do not survive later compiler resets.
+        ArrayList<Type> inputs = new ArrayList<>(Arrays.asList(
+            Type.BOTTOM,Type.CONTROL,Type.NIL,TypeScalar.BOT,TypePtr.PTR,
+            TypeMemPtr.BOT,TypeFunPtr.BOT,TypeMem.BOT,
+            TypeConAryB.make(new byte[]{1,2,3})));
+        TypeInteger.gather(inputs);
+        TypeFloat.gather(inputs);
+        int size = inputs.size();
+        for( int i=0; i<size; i++ ) inputs.add(inputs.get(i).dual());
+        for( long value : new long[]{Long.MIN_VALUE,Long.MIN_VALUE+1,-1,1,Long.MAX_VALUE} )
+            inputs.add(TypeInteger.constant(value));
+        for( double value : new double[]{-0.0,0.0,-1.0,1.0,Double.NaN,Double.NEGATIVE_INFINITY,Double.POSITIVE_INFINITY} )
+            inputs.add(TypeFloat.constant(value));
+        Type[][] expected = new Type[3][inputs.size()];
+        for( CodeGen.Phase phase : new CodeGen.Phase[]{CodeGen.Phase.Parse,CodeGen.Phase.Iter,CodeGen.Phase.Opto,CodeGen.Phase.IterPostOpto} ) {
+            code.driver(phase);
+            for( byte mode=0; mode<3; mode++ ) {
+                // An isolated analysis input: vary its type without peepholes
+                // selecting a mode or folding the node under test.
+                Node input = new ConstantNode(Type.BOTTOM);
+                input.setDef(0,null);
+                MinusNode minus = new MinusNode(input,mode);
+                Type[] results = new Type[inputs.size()];
+                for( int i=0; i<inputs.size(); i++ ) {
+                    input._type = inputs.get(i);
+                    results[i] = minus.compute();
+                    if( phase==CodeGen.Phase.Parse ) expected[mode][i] = results[i];
+                    else assertSame("Phase changed compute",expected[mode][i],results[i]);
+                }
+                // The same order relation covers both falling SCCP types
+                // and rising Iter types, including crossing numeric families.
+                for( int i=0; i<inputs.size(); i++ )
+                    for( int j=0; j<inputs.size(); j++ )
+                        if( inputs.get(i).isa(inputs.get(j)) )
+                            assertTrue("mode="+mode+": "+inputs.get(i)+" -> "+inputs.get(j)+
+                                       " gave "+results[i]+" -> "+results[j],results[i].isa(results[j]));
+            }
+        }
+    }
+
+    @Test public void testUnresolvedInput() {
+        new CodeGen("return 0;").driver(CodeGen.Phase.Opto);
+        Node input = new ConstantNode(TypeInteger.TRUE);
+        MinusNode minus = new MinusNode(input);
+        assertSame(TypeInteger.constant(-1),minus.compute());
+        input._type = Type.BOTTOM;
+        assertSame(Type.BOTTOM,minus.compute());
+        minus.setMode((byte)1);
+        assertSame(Type.BOTTOM,minus.compute());
+    }
+
+    @Test public void testRecursiveFloat() {
+        CodeGen code = new CodeGen("val _neg = { int x -> x ? -_neg(x-1) : 1.0; }; return _neg(arg);")
+            .driver(CodeGen.Phase.TypeCheck);
+        for( int i=0; i<4; i++ )
+            assertEquals((i&1)==0 ? "1.0" : "-1.0",Eval2.eval(code,i));
+    }
+}
-- 
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