Almost-constant interceptors

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

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of ssa;
 
 class SsaCodeGeneratorTask extends CompilerTask {
 
   final JavaScriptBackend backend;
 
@@ skipping 1454 matching lines @@
     // branches, and is not the join block.
     // Depending on how the then/else branches terminate
     // (e.g., return/throw/break) there can be any number of these.
     List<HBasicBlock> dominated = node.block.dominatedBlocks;
     for (int i = 2; i < dominated.length; i++) {
       visitBasicBlock(dominated[i]);
     }
   }
 
   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) {
     use(node.receiver);
     js.Expression object = pop();
     String name = node.selector.name;
     String methodName;
     List<js.Expression> arguments = visitArguments(node.inputs);
     Element target = node.element;
 
@@ skipping 1174 matching lines @@
   js.PropertyAccess accessHelper(String name) {
     Element helper = backend.findHelper(name);
     if (helper == null) {
       // For mocked-up tests.
       return js.js('(void 0).$name');
     }
     registry.registerStaticUse(helper);
     return backend.emitter.staticFunctionAccess(helper);
   }
 }