Make HCheckPrototypeMaps compatible with parallel recompilation.

src/x64/lithium-codegen-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // 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 4760 matching lines @@
   __ ClampUint8(input_reg);
 
   __ bind(&done);
 }
 
 
 void LCodeGen::DoCheckPrototypeMaps(LCheckPrototypeMaps* instr) {
   ASSERT(instr->temp()->Equals(instr->result()));
   Register reg = ToRegister(instr->temp());
 
-  Handle<JSObject> holder = instr->holder();
-  Handle<JSObject> current_prototype = instr->prototype();
+  ZoneList<Handle<JSObject> >* prototypes = instr->prototypes();
+  ZoneList<Handle<Map> >* maps = instr->maps();
 
-  // Load prototype object.
-  __ LoadHeapObject(reg, current_prototype);
+  ASSERT(prototypes->length() == maps->length());
 
-  // Check prototype maps up to the holder.
-  while (!current_prototype.is_identical_to(holder)) {
-    DoCheckMapCommon(reg, Handle<Map>(current_prototype->map()),
-                     ALLOW_ELEMENT_TRANSITION_MAPS, instr);
-    current_prototype =
-        Handle<JSObject>(JSObject::cast(current_prototype->GetPrototype()));
-    // Load next prototype object.
-    __ LoadHeapObject(reg, current_prototype);
+  for (int i = 0; i < prototypes->length(); i++) {
+    __ LoadHeapObject(reg, prototypes->at(i));
+    DoCheckMapCommon(reg, maps->at(i), ALLOW_ELEMENT_TRANSITION_MAPS, instr);
   }
-
-  // Check the holder map.
-    DoCheckMapCommon(reg, Handle<Map>(current_prototype->map()),
-                     ALLOW_ELEMENT_TRANSITION_MAPS, instr);
 }
 
 
 void LCodeGen::DoAllocateObject(LAllocateObject* instr) {
   class DeferredAllocateObject: public LDeferredCode {
    public:
     DeferredAllocateObject(LCodeGen* codegen, LAllocateObject* instr)
         : LDeferredCode(codegen), instr_(instr) { }
     virtual void Generate() { codegen()->DoDeferredAllocateObject(instr_); }
     virtual LInstruction* instr() { return instr_; }
@@ skipping 767 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64