Don't add code dependencies eagerly for HCheckMaps.

src/mips/lithium-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.7
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5146 matching lines @@
       codegen()->DoDeferredInstanceMigration(instr_, object_);
     }
     Label* check_maps() { return &check_maps_; }
     virtual LInstruction* instr() V8_OVERRIDE { return instr_; }
    private:
     LCheckMaps* instr_;
     Label check_maps_;
     Register object_;
   };
 
-  if (instr->hydrogen()->CanOmitMapChecks()) return;
+  if (instr->hydrogen()->IsStabilityCheck()) {
+    const UniqueSet<Map>* maps = instr->hydrogen()->maps();
+    for (int i = 0; i < maps->size(); ++i) {
+      AddStabilityDependency(maps->at(i).handle());
+    }
+    return;
+  }
+
   Register map_reg = scratch0();
   LOperand* input = instr->value();
   ASSERT(input->IsRegister());
   Register reg = ToRegister(input);
   __ lw(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
 
   DeferredCheckMaps* deferred = NULL;
-  if (instr->hydrogen()->has_migration_target()) {
+  if (instr->hydrogen()->HasMigrationTarget()) {
     deferred = new(zone()) DeferredCheckMaps(this, instr, reg);
     __ bind(deferred->check_maps());
   }
 
   const UniqueSet<Map>* maps = instr->hydrogen()->maps();
   Label success;
   for (int i = 0; i < maps->size() - 1; i++) {
     Handle<Map> map = maps->at(i).handle();
     __ CompareMapAndBranch(map_reg, map, &success, eq, &success);
   }
   Handle<Map> map = maps->at(maps->size() - 1).handle();
   // Do the CompareMap() directly within the Branch() and DeoptimizeIf().
-  if (instr->hydrogen()->has_migration_target()) {
+  if (instr->hydrogen()->HasMigrationTarget()) {
     __ Branch(deferred->entry(), ne, map_reg, Operand(map));
   } else {
     DeoptimizeIf(ne, instr->environment(), map_reg, Operand(map));
   }
 
   __ bind(&success);
 }
 
 
 void LCodeGen::DoClampDToUint8(LClampDToUint8* instr) {
@@ skipping 692 matching lines @@
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(deferred->exit());
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal