Whenever possible use length passed to the List constructor for bounds checks instead of loading it…

runtime/vm/flow_graph_builder.cc

 // 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.
 
 #include "vm/flow_graph_builder.h"
 
 #include "vm/ast_printer.h"
 #include "vm/code_descriptors.h"
 #include "vm/dart_entry.h"
 #include "vm/flags.h"
@@ skipping 1669 matching lines @@
                                        node->type_arguments()));
     arguments->Add(push_type_arguments);
     ASSERT(arguments->length() == 1);
     BuildPushArguments(*node->arguments(), arguments);
     StaticCallInstr* call =
         new StaticCallInstr(node->token_pos(),
                             node->constructor(),
                             node->arguments()->names(),
                             arguments);
     // List factories return kArrayCid or kGrowableObjectArrayCid.
-    call->set_result_cid(GetResultCidOfConstructor(node));
+    const intptr_t result_cid = GetResultCidOfConstructor(node);
+    call->set_result_cid(result_cid);
+    call->set_is_known_constructor(result_cid != kDynamicCid);
     ReturnDefinition(call);
     return;
   }
   // t_n contains the allocated and initialized object.
   //   t_n      <- AllocateObject(class)
   //   t_n+1    <- ctor-arg
   //   t_n+2... <- constructor arguments start here
   //   StaticCall(constructor, t_n+1, t_n+2, ...)
   // No need to preserve allocated value (simpler than in ValueGraphVisitor).
   Value* allocated_value = BuildObjectAllocation(node);
@@ skipping 929 matching lines @@
   intptr_t len = OS::SNPrint(NULL, 0, kFormat, function_name, reason) + 1;
   char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
   OS::SNPrint(chars, len, kFormat, function_name, reason);
   const Error& error = Error::Handle(
       LanguageError::New(String::Handle(String::New(chars))));
   Isolate::Current()->long_jump_base()->Jump(1, error);
 }
 
 
 }  // namespace dart