Do not patch IC in deoptimized code.

src/ic/ic-inl.h

 // Copyright 2012 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.
 
 #ifndef V8_IC_INL_H_
 #define V8_IC_INL_H_
 
 #include "src/ic/ic.h"
 
 #include "src/compiler.h"
@@ skipping 77 matching lines @@
   // Convert target address to the code object. Code::GetCodeFromTargetAddress
   // is safe for use during GC where the map might be marked.
   Code* result = Code::GetCodeFromTargetAddress(target);
   DCHECK(result->is_inline_cache_stub());
   return result;
 }
 
 
 void IC::SetTargetAtAddress(Address address, Code* target,
                             ConstantPoolArray* constant_pool) {
+  if (AddressIsDeoptimizedCode(target->GetIsolate(), address)) return;
+
   DCHECK(target->is_inline_cache_stub() || target->is_compare_ic_stub());
 
   // Don't use this for load_ics when --vector-ics is turned on.
   DCHECK(!target->is_inline_cache_stub() ||
          (target->kind() != Code::LOAD_IC &&
           target->kind() != Code::KEYED_LOAD_IC));
 
   Heap* heap = target->GetHeap();
   Code* old_target = GetTargetAtAddress(address, constant_pool);
 #ifdef DEBUG
@@ skipping 97 matching lines @@
   JSFunction* builtin_ctor = GetRootConstructor(*map, native_context);
   if (builtin_ctor != NULL) {
     *flag = kCacheOnPrototype;
     return handle(builtin_ctor->initial_map());
   }
   *flag = kCacheOnReceiver;
   return map;
 }
 
 
-inline Code* IC::get_host() {
+Code* IC::get_host() {
   return isolate()
       ->inner_pointer_to_code_cache()
       ->GetCacheEntry(address())
       ->code;
 }
+
+
+bool IC::AddressIsDeoptimizedCode() const {
+  return AddressIsDeoptimizedCode(isolate(), address());
+}
+
+
+bool IC::AddressIsDeoptimizedCode(Isolate* isolate, Address address) {
+  Code* host =
+      isolate->inner_pointer_to_code_cache()->GetCacheEntry(address)->code;
+  return (host->kind() == Code::OPTIMIZED_FUNCTION &&
+          host->marked_for_deoptimization());
+}
 }
 }  // namespace v8::internal
 
 #endif  // V8_IC_INL_H_