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

vm/flow_graph_compiler_x64.cc

Index: vm/flow_graph_compiler_x64.cc
===================================================================
--- vm/flow_graph_compiler_x64.cc	(revision 8524)
+++ vm/flow_graph_compiler_x64.cc	(working copy)
@@ -994,13 +994,15 @@
   __ 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);