Almost-constant interceptors

pkg/compiler/lib/src/ssa/codegen.dart

Index: pkg/compiler/lib/src/ssa/codegen.dart
diff --git a/pkg/compiler/lib/src/ssa/codegen.dart b/pkg/compiler/lib/src/ssa/codegen.dart
index 60403c3c56617bff3fd136a2943688f4a4d2a320..ea200c3cb337ce2af6834488c480f7351e302bed 100644
--- a/pkg/compiler/lib/src/ssa/codegen.dart
+++ b/pkg/compiler/lib/src/ssa/codegen.dart
@@ -1472,14 +1472,25 @@ class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
   }
 
   void visitInterceptor(HInterceptor node) {
-    registry.registerSpecializedGetInterceptor(node.interceptedClasses);
-    String name = backend.namer.nameForGetInterceptor(node.interceptedClasses);
-    var isolate = new js.VariableUse(
-        backend.namer.globalObjectFor(backend.interceptorsLibrary));
-    use(node.receiver);
-    List<js.Expression> arguments = <js.Expression>[pop()];
-    push(js.propertyCall(isolate, name, arguments), node);
-    registry.registerUseInterceptor();
+    if (node.isConditionalConstantInterceptor) {
+      assert(node.inputs.length == 2);
+      use(node.receiver);
+      js.Expression receiverExpression = pop();
+      use(node.conditionalConstantInterceptor);
+      js.Expression constant = pop();
+      push(js.js('# && #', [receiverExpression, constant]));
+    } else {
+      assert(node.inputs.length == 1);
+      registry.registerSpecializedGetInterceptor(node.interceptedClasses);
+      String name =
+          backend.namer.nameForGetInterceptor(node.interceptedClasses);
+      var isolate = new js.VariableUse(
+          backend.namer.globalObjectFor(backend.interceptorsLibrary));
+      use(node.receiver);
+      List<js.Expression> arguments = <js.Expression>[pop()];
+      push(js.propertyCall(isolate, name, arguments), node);
+      registry.registerUseInterceptor();
+    }
   }
 
   visitInvokeDynamicMethod(HInvokeDynamicMethod node) {