- Do not use near jumps for large number of sequential class id

vm/flow_graph_compiler_x64.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/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "lib/error.h"
@@ skipping 976 matching lines @@
 void FlowGraphCompiler::EmitClassChecksNoSmi(
     const ZoneGrowableArray<intptr_t>& class_ids,
     Register instance_reg,
     Register temp_reg,
     Label* deopt) {
   Label ok;
   ASSERT(class_ids[0] != kSmi);
   __ testq(instance_reg, Immediate(kSmiTagMask));
   __ j(ZERO, deopt);
   Label is_ok;
+  bool jump_style = (class_ids.length() < 5) ?
+      Assembler::kNearJump : Assembler::kFarJump;
   __ LoadClassId(temp_reg, instance_reg);
   for (intptr_t i = 0; i < class_ids.length(); i++) {
     __ cmpl(temp_reg, Immediate(class_ids[i]));
     if (i == (class_ids.length() - 1)) {
       __ j(NOT_EQUAL, deopt);
     } else {
-      __ j(EQUAL, &is_ok, Assembler::kNearJump);
+      __ j(EQUAL, &is_ok, jump_style);
     }
   }
   __ Bind(&is_ok);
 }
 
 
 void FlowGraphCompiler::LoadDoubleOrSmiToXmm(XmmRegister result,
                                              Register reg,
                                              Register temp,
                                              Label* not_double_or_smi) {
@@ skipping 10 matching lines @@
   __ cvtsi2sd(result, temp);
   __ Bind(&done);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64