Fix vs0 bugs

Use a BoolNode.NE instead of inverting outputs; the outputs are already matched and cannot be inverted.
Use a `swap` not an `invert` when switching sides in a compare.

5 files changed, 35 insertions, 8 deletions

diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter21/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index f5f6a1de..fd6448a2 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -92,6 +92,18 @@ abstract public class BoolNode extends Node {
         Node copyF() { return new EQF(null,null); }
     }
 
+    public static class NE extends BoolNode {
+        public NE(Node lhs, Node rhs) { super(lhs,rhs); }
+        public String op() { return "!="; }
+        TypeInteger doOp(TypeInteger i1, TypeInteger i2) {
+            if( i1==i2 && i1.isConstant() ) return TRUE;
+            if( i1._max < i2._min || i1._min > i2._max ) return FALSE;
+            return BOOL;
+        }
+        Node copy(Node lhs, Node rhs) { return new NE(lhs,rhs); }
+        Node copyF() { throw Utils.TODO(); }
+    }
+
     public static class LT extends BoolNode {
         public LT(Node lhs, Node rhs) { super(lhs,rhs); }
         public String op() { return "<" ; }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/IfNode.java b/chapter21/src/main/java/com/seaofnodes/simple/node/IfNode.java
index c65e9a3b..f00f4f9f 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/IfNode.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/IfNode.java
@@ -69,6 +69,7 @@ public class IfNode extends CFGNode implements MultiNode {
     // The following CProjs will be inverted by the caller.
     public void invert() { throw Utils.TODO(); }
 
+    // Negate the sense of a test
     public static String invert( String bop ) {
         return switch( bop ) {
         case "<"  -> ">=";
@@ -80,4 +81,17 @@ public class IfNode extends CFGNode implements MultiNode {
         default -> throw Utils.TODO();
         };
     }
+
+    // Swap compare operands
+    public static String swap( String bop ) {
+        return switch( bop ) {
+        case "<"  -> ">" ;
+        case "<=" -> ">=";
+        case "==" -> "!=";
+        case "!=" -> "==";
+        case ">"  -> "<" ;
+        case ">=" -> "<=";
+        default -> throw Utils.TODO();
+        };
+    }
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java
index 36e32bb8..b684b4c4 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java
@@ -30,7 +30,7 @@ public class SetX86 extends MachConcreteNode implements MachNode {
         enc.add1(switch (_bop) {
             case "==" -> 0x94;  // SETE
             case "<"  -> 0x9C;  // SETL
-            case "<=" -> 0X9E;  // SETLE
+            case "<=" -> 0x96; //0X9E;  // SETLE
             default -> throw Utils.TODO();
             });
         enc.add1(x86_64_v2.modrm(x86_64_v2.MOD.DIRECT, 0, dst));
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SplitX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SplitX86.java
index f474b431..073d1d9b 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SplitX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SplitX86.java
@@ -77,13 +77,14 @@ public class SplitX86 extends SplitNode {
             enc.add1(0x0F);
             enc.add1(0x28);
         } else if( dstX && !srcX ) {
-            // xmm->reg (66 REX.W 0F 6E /r MOVQ xmm, r/m64)
+            // reg->xmm (66 REX.W 0F 6E /r MOVQ xmm, r/m64)
             enc.add1(0x0F);
             enc.add1(0x6E);
         } else if( !dstX && srcX ) {
-            // reg->xmm(66 REX.W 0F 7E /r MOVQ r/m64, xmm)
+            // xmm->reg(66 0F 7E /r MOVQ r/m64, xmm)
             enc.add1(0x0F);
             enc.add1(0x7E);
+            short tmp=src; src=dst; dst=tmp;
         }
 
         enc.add1(x86_64_v2.modrm(x86_64_v2.MOD.DIRECT, dst, src));
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
index bf8f92ad..98b14a3c 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
@@ -502,11 +502,11 @@ public class x86_64_v2 extends Machine {
 
     // Because X86 flags, a normal ideal Bool is 2 X86 ops: a "cmp" and at "setz".
     // Ideal If reading from a setz will skip it and use the "cmp" instead.
-    private static boolean invert;
+    private static boolean swap;
     private Node cmp( BoolNode bool ) {
-        invert = false;
+        swap = false;
         Node cmp = _cmp(bool);
-        return new SetX86(cmp, invert ? IfNode.invert(bool.op()) : bool.op());
+        return new SetX86(cmp, swap ? IfNode.swap(bool.op()) : bool.op());
     }
 
     private Node _cmp(BoolNode bool) {
@@ -528,7 +528,7 @@ public class x86_64_v2 extends Machine {
             return new CmpIX86(bool, (int)ti.value());
 
         if( lhs instanceof ConstantNode con && con._con instanceof TypeInteger ti && imm32(ti.value()) ) {
-            invert = true;
+            swap = true;
             return new CmpIX86(bool, (int)ti.value(), 0.5);
         }
 
@@ -560,7 +560,7 @@ public class x86_64_v2 extends Machine {
         // Loads do not set the flags, and will need an explicit TEST
         BoolNode bool;
         if( iff.in(1) instanceof BoolNode bool0 ) bool = bool0;
-        else iff.setDef(1, bool=new BoolNode.EQ(iff.in(1), new ConstantNode(TypeInteger.ZERO)));
+        else iff.setDef(1, bool=new BoolNode.NE(iff.in(1), new ConstantNode(TypeInteger.ZERO)));
         return new JmpX86(iff, bool.op());
     }