Reland 'Do not embed constant functions in StoreTransition stub.'

src/ic/handler-compiler.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/ic/call-optimization.h"
 #include "src/ic/handler-compiler.h"
 #include "src/ic/ic.h"
 #include "src/ic/ic-inl.h"
@@ skipping 312 matching lines @@
       iter.Advance();
     }
     if (!last.is_null()) set_holder(last);
     NonexistentFrontendHeader(name, &miss, scratch1(), scratch2());
   } else {
     FrontendHeader(receiver(), name, &miss);
     DCHECK(holder()->HasFastProperties());
   }
 
   int descriptor = transition->LastAdded();
-  DescriptorArray* descriptors = transition->instance_descriptors();
+  Handle<DescriptorArray> descriptors(transition->instance_descriptors());

[ulan, 2014/12/09 17:30:37]

This is the only diff from the original CL. We need to use handle here because
GenerateRestoreMap below can cause GC.

   PropertyDetails details = descriptors->GetDetails(descriptor);
   Representation representation = details.representation();
   DCHECK(!representation.IsNone());
 
   // Stub is never generated for objects that require access checks.
   DCHECK(!transition->is_access_check_needed());
 
   // Call to respective StoreTransitionStub.
   if (details.type() == CONSTANT) {
-    GenerateConstantCheck(descriptors->GetValue(descriptor), value(), &miss);
-
     GenerateRestoreMap(transition, scratch2(), &miss);
+    DCHECK(descriptors->GetValue(descriptor)->IsJSFunction());
+    Register map_reg = StoreTransitionDescriptor::MapRegister();
+    GenerateConstantCheck(map_reg, descriptor, value(), scratch2(), &miss);
     GenerateRestoreName(name);
     StoreTransitionStub stub(isolate());
     GenerateTailCall(masm(), stub.GetCode());
 
   } else {
     if (representation.IsHeapObject()) {
       GenerateFieldTypeChecks(descriptors->GetFieldType(descriptor), value(),
                               &miss);
     }
     StoreTransitionStub::StoreMode store_mode =
@@ skipping 79 matching lines @@
         DCHECK(elements_kind == DICTIONARY_ELEMENTS);
         cached_stub = LoadDictionaryElementStub(isolate()).GetCode();
       }
     }
 
     handlers->Add(cached_stub);
   }
 }
 }
 }  // namespace v8::internal