Use MemoryChunk-based allocation for deoptimization entry code

src/deoptimizer.h

 // 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 84 matching lines @@
   DeoptimizerData();
   ~DeoptimizerData();
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   void Iterate(ObjectVisitor* v);
 #endif
 
  private:
   int eager_deoptimization_entry_code_entries_;
   int lazy_deoptimization_entry_code_entries_;
+#if defined(V8_TARGET_ARCH_X64)

[Sven Panne, 2012/12/14 08:08:40]

Having architecture-specific stuff here in the architecture-independent parts is
the wrong approach, leading into the wrong direction. I would strongly object
any such change...

Our goal should be making the deoptimizer code more architecture-independent, we
already have *tons* of duplicated boilerplate code.

+  Address eager_deoptimization_entry_start_;

[danno, 2012/12/20 10:18:35]

Is there any reason why this shouldn't work identically on all platforms, taking
the deopt tables from the CodeSpace? If not, please make this cross platform.

+  size_t eager_deoptimization_reserved_size_;
+  MemoryChunk* eager_deoptimization_entry_code_;
+  Address lazy_deoptimization_entry_start_;
+  size_t lazy_deoptimization_reserved_size_;
+  MemoryChunk* lazy_deoptimization_entry_code_;
+#else
   VirtualMemory* eager_deoptimization_entry_code_;
   VirtualMemory* lazy_deoptimization_entry_code_;
+#endif
   Deoptimizer* current_;
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   DeoptimizedFrameInfo* deoptimized_frame_info_;
 #endif
 
   // List of deoptimized code which still have references from active stack
   // frames. These code objects are needed by the deoptimizer when deoptimizing
   // a frame for which the code object for the function function has been
   // changed from the code present when deoptimizing was done.
@@ skipping 298 matching lines @@
   JSFunction* GetFunction() const { return function_; }
 
   unsigned GetOffsetFromSlotIndex(int slot_index);
 
   intptr_t GetFrameSlot(unsigned offset) {
     return *GetFrameSlotPointer(offset);
   }
 
   double GetDoubleFrameSlot(unsigned offset) {
     intptr_t* ptr = GetFrameSlotPointer(offset);
 #if V8_TARGET_ARCH_MIPS

[Sven Panne, 2012/12/14 08:08:40]

Not from this CL, but the same comment holds. This should be moved/refactored.

     // Prevent gcc from using load-double (mips ldc1) on (possibly)
     // non-64-bit aligned double. Uses two lwc1 instructions.
     union conversion {
       double d;
       uint32_t u[2];
     } c;
     c.u[0] = *reinterpret_cast<uint32_t*>(ptr);
     c.u[1] = *(reinterpret_cast<uint32_t*>(ptr) + 1);
     return c.d;
 #else
@@ skipping 410 matching lines @@
   Object** expression_stack_;
   int source_position_;
 
   friend class Deoptimizer;
 };
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_DEOPTIMIZER_H_