Folding of bounded dynamic size allocations with const size allocations.

src/hydrogen-instructions.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_HYDROGEN_INSTRUCTIONS_H_
 #define V8_HYDROGEN_INSTRUCTIONS_H_
 
 #include "v8.h"
 
 #include "allocation.h"
@@ skipping 5558 matching lines @@
     }
     return flags;
   }
 
   void UpdateClearNextMapWord(bool clear_next_map_word) {
     flags_ = static_cast<Flags>(clear_next_map_word
                                 ? flags_ | CLEAR_NEXT_MAP_WORD
                                 : flags_ & ~CLEAR_NEXT_MAP_WORD);
   }
 
-  void UpdateSize(HValue* size) {
+  void UpdateSize(HValue* size, HConstant* size_upper_bound = NULL) {
     SetOperandAt(1, size);
     if (size->IsInteger32Constant()) {
       size_upper_bound_ = HConstant::cast(size);
     } else {
-      size_upper_bound_ = NULL;
+      size_upper_bound_ = size_upper_bound;
     }
   }
 
   HAllocate* GetFoldableDominator(HAllocate* dominator);
 
   void UpdateFreeSpaceFiller(int32_t filler_size);
 
   void CreateFreeSpaceFiller(int32_t filler_size);
 
   bool IsFoldable(HAllocate* allocate) {
     return (IsNewSpaceAllocation() && allocate->IsNewSpaceAllocation()) ||
         (IsOldDataSpaceAllocation() && allocate->IsOldDataSpaceAllocation()) ||
         (IsOldPointerSpaceAllocation() &&
             allocate->IsOldPointerSpaceAllocation());
   }
 
-  void ClearNextMapWord(int offset);
+  void ClearNextMapWord(HValue* offset);
 
   Flags flags_;
   Handle<Map> known_initial_map_;
   HAllocate* dominating_allocate_;
   HStoreNamedField* filler_free_space_size_;
   HConstant* size_upper_bound_;
 };
 
 
 class HStoreCodeEntry V8_FINAL: public HTemplateInstruction<2> {
@@ skipping 2117 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_