dart2js cps_ir: Use interceptors for is-checks (version 2)

pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart

Index: pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
index 19b0543c179877ab2a4d7ba2c7061d8822b6f116..dbc84fb2479f84f99196b9ada33b08f26725e543 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
@@ -587,6 +587,7 @@ class Refinement extends Primitive {
 /// to simplify code generation for type tests.
 class TypeTest extends Primitive {
   Reference<Primitive> value;
+

[Kevin Millikin (Google), 2015/10/07 14:10:49]

Not sure why there's a space here (there isn't one in the parallel class
TypeTestViaFlag below).

[sra1, 2015/10/07 17:45:57]

Done.

   final DartType dartType;
 
   /// If [type] is an [InterfaceType], this holds the internal representation of

[Kevin Millikin (Google), 2015/10/07 14:10:49]

Hmm, [type] in the doc comment didn't get renamed when type was renamed to
dartType.  Could you add that to this change since you're touching the code?

[sra1, 2015/10/07 17:45:58]

Done.

@@ -602,11 +603,13 @@ class TypeTest extends Primitive {
   /// Otherwise the list is empty.
   final List<Reference<Primitive>> typeArguments;
 
+  Reference<Primitive> interceptor;

[Kevin Millikin (Google), 2015/10/07 14:10:49]

Needs some documentation: how do I interpret a non-null interceptor?  A null
interceptor?

[sra1, 2015/10/07 17:45:58]

Done.

+
   TypeTest(Primitive value,
            this.dartType,
            List<Primitive> typeArguments)
-  : this.value = new Reference<Primitive>(value),
-    this.typeArguments = _referenceList(typeArguments);
+      : this.value = new Reference<Primitive>(value),
+        this.typeArguments = _referenceList(typeArguments);
 
   accept(Visitor visitor) => visitor.visitTypeTest(this);
 
@@ -614,6 +617,22 @@ class TypeTest extends Primitive {
   bool get isSafeForReordering => true;
 }
 
+/// An "is" type test for a raw type, performed by testing a flag property.
+///
+/// Returns `true` if [interceptor] is for [dartType].
+class TypeTestViaFlag extends Primitive {
+  Reference<Primitive> interceptor;
+  final DartType dartType;
+
+  TypeTestViaFlag(Primitive interceptor, this.dartType)
+      : this.interceptor = new Reference<Primitive>(interceptor);
+
+  accept(Visitor visitor) => visitor.visitTypeTestViaFlag(this);
+
+  bool get isSafeForElimination => true;
+  bool get isSafeForReordering => true;
+}
+
 /// An "as" type cast.
 ///
 /// If [value] is `null` or is an instance of [type], [continuation] is invoked
@@ -1371,6 +1390,7 @@ abstract class Visitor<T> {
   T visitTypeExpression(TypeExpression node);
   T visitCreateInvocationMirror(CreateInvocationMirror node);
   T visitTypeTest(TypeTest node);
+  T visitTypeTestViaFlag(TypeTestViaFlag node);
   T visitApplyBuiltinOperator(ApplyBuiltinOperator node);
   T visitApplyBuiltinMethod(ApplyBuiltinMethod node);
   T visitGetLength(GetLength node);
@@ -1496,9 +1516,16 @@ class LeafVisitor implements Visitor {
   visitTypeTest(TypeTest node) {
     processTypeTest(node);
     processReference(node.value);
+    if (node.interceptor != null) processReference(node.interceptor);
     node.typeArguments.forEach(processReference);
   }
 
+  processTypeTestViaFlag(TypeTestViaFlag node) {}
+  visitTypeTestViaFlag(TypeTestViaFlag node) {
+    processTypeTestViaFlag(node);
+    processReference(node.interceptor);
+  }
+
   processSetMutable(SetMutable node) {}
   visitSetMutable(SetMutable node) {
     processSetMutable(node);