2 more encoding bugs

Missing constant NIL, arm CAST

7 files changed, 46 insertions, 7 deletions

diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/CastARM.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/CastARM.java
new file mode 100644
index 00000000..a5a4e112
--- /dev/null
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/CastARM.java
@@ -0,0 +1,18 @@
+package com.seaofnodes.simple.node.cpus.arm;
+
+import com.seaofnodes.simple.SB;
+import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.codegen.Encoding;
+import com.seaofnodes.simple.codegen.RegMask;
+import com.seaofnodes.simple.node.CastNode;
+import com.seaofnodes.simple.node.MachNode;
+
+public class CastARM extends CastNode implements MachNode {
+    public CastARM( CastNode cast ) { super(cast); }
+    @Override public String op() { return label(); }
+    @Override public RegMask regmap(int i) { assert i==1; return RegMask.FULL; }
+    @Override public RegMask outregmap() { return RegMask.FULL; }
+    @Override public int twoAddress( ) { return 1; }
+    @Override public void encoding( Encoding enc ) { }
+    @Override public void asm(CodeGen code, SB sb) { _t.print(sb.p(code.reg(in(1))).p(" isa ")); }
+}
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/IntARM.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/IntARM.java
index 8affb4c6..0a07b07a 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/IntARM.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/IntARM.java
@@ -4,6 +4,7 @@ import com.seaofnodes.simple.*;
 import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.node.ConstantNode;
 import com.seaofnodes.simple.node.MachNode;
+import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeInteger;
 
 // Integer constants
@@ -19,7 +20,7 @@ public class IntARM extends ConstantNode implements MachNode {
 
     @Override public void encoding( Encoding enc ) {
         short self = enc.reg(this);
-        long x = ((TypeInteger)_con).value();
+        long x = _con==Type.NIL ? 0 : ((TypeInteger)_con).value();
         int nb0 = 0;
         int nb1 = 0;
         // Count number of 0000 and FFFF blocks
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java
index 0aea0ae9..bedda4e2 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java
@@ -620,7 +620,7 @@ public class arm extends Machine {
         case AndNode and    -> and(and);
         case BoolNode bool  -> cmp(bool);
         case CallNode call  -> call(call);
-        case CastNode cast  -> new CastNode(cast);
+        case CastNode cast  -> new CastARM(cast);
         case CallEndNode cend -> new CallEndARM(cend);
         case CProjNode c    -> new CProjNode(c);
         case ConstantNode con -> con(con);
@@ -696,7 +696,7 @@ public class arm extends Machine {
             : new SubARM(sub);
     }
 
-    private Node con(ConstantNode con) {
+    private Node con( ConstantNode con ) {
         if( !con._con.isConstant() ) return new ConstantNode( con ); // Default unknown caller inputs
         return switch( con._con ) {
         case TypeInteger ti  -> new IntARM(con);
@@ -705,7 +705,7 @@ public class arm extends Machine {
         case TypeMemPtr tmp -> new ConstantNode(con);
         case TypeNil tn  -> throw Utils.TODO();
         // TOP, BOTTOM, XCtrl, Ctrl, etc.  Never any executable code.
-        case Type t -> new ConstantNode(con);
+        case Type t -> t==Type.NIL ? new IntARM(con) : new ConstantNode(con);
         };
     }
 
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/IntRISC.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/IntRISC.java
index 764c49e6..70d5c18f 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/IntRISC.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/IntRISC.java
@@ -4,6 +4,7 @@ import com.seaofnodes.simple.*;
 import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.node.ConstantNode;
 import com.seaofnodes.simple.node.MachNode;
+import com.seaofnodes.simple.type.Type;
 import com.seaofnodes.simple.type.TypeInteger;
 
 // 12-bit integer constant.  Larger constants are made up in the instruction
@@ -17,10 +18,10 @@ public class IntRISC extends ConstantNode implements MachNode {
     @Override public IntRISC copy() { return new IntRISC(this); }
     @Override public void encoding( Encoding enc ) {
         short dst  = enc.reg(this);
-        TypeInteger ti = (TypeInteger)_con;
+        int val = _con==Type.NIL ? 0 : (int)(((TypeInteger)_con).value() & 0xFFF);
         // Explicit truncation of larger immediates; this will sign-extend on
         // load and this is handled during instruction selection.
-        enc.add4(riscv.i_type(riscv.OP_IMM, dst, 0, riscv.ZERO, (int)(ti.value() & 0xFFF)));
+        enc.add4(riscv.i_type(riscv.OP_IMM, dst, 0, riscv.ZERO, val));
     }
     @Override public void asm(CodeGen code, SB sb) {
         String reg = code.reg(this);
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 b4c382c5..12b3a12c 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
@@ -573,7 +573,7 @@ public class x86_64_v2 extends Machine {
         return new CmpX86(bool);
     }
 
-    private Node con(ConstantNode con) {
+    private Node con( ConstantNode con ) {
         if(!con._con.isConstant()) return new ConstantNode(con); // Default unknown caller inputs
         return switch (con._con) {
             case TypeInteger ti -> new IntX86(con);
diff --git a/chapter21/src/test/java/com/seaofnodes/simple/Chapter21Test.java b/chapter21/src/test/java/com/seaofnodes/simple/Chapter21Test.java
index 0610d294..e584f9bc 100644
--- a/chapter21/src/test/java/com/seaofnodes/simple/Chapter21Test.java
+++ b/chapter21/src/test/java/com/seaofnodes/simple/Chapter21Test.java
@@ -64,6 +64,14 @@ public class Chapter21Test {
         testCPU(src,"arm"      , "SystemV",19,null);
     }
 
+    @Test
+    public void testAntiDeps1() throws IOException {
+        String src = Files.readString(Path.of("src/test/java/com/seaofnodes/simple/progs/antiDep1.smp"));
+        testCPU(src,"x86_64_v2", "SystemV", 3,"return mov(mov(S));");
+        testCPU(src,"riscv"    , "SystemV",10,"return mov(mov(S));");
+        testCPU(src,"arm"      , "SystemV",10,"return mov(mov(S));");
+    }
+
     @Test public void testNewtonExport() throws IOException {
         String result = """
 0  0.000000
diff --git a/chapter21/src/test/java/com/seaofnodes/simple/progs/antiDep1.smp b/chapter21/src/test/java/com/seaofnodes/simple/progs/antiDep1.smp
new file mode 100644
index 00000000..b18dfd16
--- /dev/null
+++ b/chapter21/src/test/java/com/seaofnodes/simple/progs/antiDep1.smp
@@ -0,0 +1,11 @@
+// -*- mode: java;  -*-
+struct S { int f; };
+var v0 = new S;
+S? v1;
+if (arg) v1 = new S;
+if (v1) {
+    v0.f = v1.f;
+} else {
+    v0.f = 2;
+}
+return v0;