Reland "VM: Simplify lowering of is-tests.""

runtime/vm/kernel_to_il.cc

 // Copyright (c) 2016, 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.
 
 #include <map>
 #include <set>
 #include <string>
 
 #include "vm/kernel_to_il.h"
 
@@ skipping 5009 matching lines @@
     if (!type.IsInstantiated()) {
       instructions += LoadInstantiatorTypeArguments();
     } else {
       instructions += NullConstant();
     }
     instructions += PushArgument();  // Type arguments.
 
     instructions += Constant(type);
     instructions += PushArgument();  // Type.
 
-    instructions += Constant(Bool::False());
-    instructions += PushArgument();  // Negate?.
-
     instructions +=
         InstanceCall(node->position(),
                      dart::Library::PrivateCoreLibName(Symbols::_instanceOf()),
-                     Token::kIS, 4);
+                     Token::kIS, 3);
   }
 
   fragment_ = instructions;
 }
 
 
 void FlowGraphBuilder::VisitAsExpression(AsExpression* node) {
   Fragment instructions = TranslateExpression(node->operand());
 
   // The VM does not like an Object_as call with a dynamic type. We need to
@@ skipping 1069 matching lines @@
       if (type_guard->IsMalformed()) {
         catch_body += ThrowTypeError();
         catch_body += Drop();
       } else {
         catch_body += LoadLocal(CurrentException());
         catch_body += PushArgument();  // exception
         catch_body += NullConstant();
         catch_body += PushArgument();  // type arguments
         catch_body += Constant(*type_guard);
         catch_body += PushArgument();  // guard type
-        catch_body += Constant(Object::bool_false());
-        catch_body += PushArgument();  // negate
         catch_body += InstanceCall(
             TokenPosition::kNoSource,
             dart::Library::PrivateCoreLibName(Symbols::_instanceOf()),
-            Token::kIS, 4);
+            Token::kIS, 3);
 
         TargetEntryInstr* catch_entry;
         TargetEntryInstr* next_catch_entry;
         catch_body += BranchIfTrue(&catch_entry, &next_catch_entry);
 
         Fragment(catch_entry) + catch_handler_body;
         catch_body = Fragment(next_catch_entry);
       }
     } else {
       catch_body += catch_handler_body;
@@ skipping 302 matching lines @@
     thread->clear_sticky_error();
     return error.raw();
   }
 }
 
 
 }  // namespace kernel
 }  // namespace dart
 
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)