VM: Improve polymorphic check-class in optimized code.

runtime/vm/flow_graph_compiler_x64.cc

 // Copyright (c) 2013, 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/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 1498 matching lines @@
                                         const Array& argument_names,
                                         Label* deopt,
                                         intptr_t deopt_id,
                                         intptr_t token_index,
                                         LocationSummary* locs) {
   ASSERT(is_optimizing());
   ASSERT(!ic_data.IsNull() && (ic_data.NumberOfUsedChecks() > 0));
   Label match_found;
   const intptr_t len = ic_data.NumberOfChecks();
   GrowableArray<CidTarget> sorted(len);
-  SortICDataByCount(ic_data, &sorted);
+  SortICDataByCount(ic_data, &sorted, /* drop_smi = */ false);
   ASSERT(class_id_reg != R10);
   ASSERT(len > 0);  // Why bother otherwise.
   const Array& arguments_descriptor =
       Array::ZoneHandle(ArgumentsDescriptor::New(argument_count,
                                                  argument_names));
   StubCode* stub_code = isolate()->stub_code();
 
   __ LoadObject(R10, arguments_descriptor, PP);
   for (intptr_t i = 0; i < len; i++) {
     const bool is_last_check = (i == (len - 1));
@@ skipping 254 matching lines @@
   __ movups(reg, Address(RSP, 0));
   __ AddImmediate(RSP, Immediate(kFpuRegisterSize), PP);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64