Improve algorithm for detaching and attaching a virtual frame to the code...

src/register-allocator.h

 // Copyright 2008 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 225 matching lines @@
 
   // Record that a register will no longer be used by decrementing its
   // reference count.
   void Unuse(Register reg) {
     ASSERT(!reg.is(no_reg));
     ASSERT(is_used(reg.code()));
     ref_counts_[reg.code()]--;
   }
 
   // Copy the reference counts from this register file to the other.
-  void CopyTo(RegisterFile* other);
+  void CopyTo(RegisterFile* other) {
+    for (int i = 0; i < kNumRegisters; i++) {
+      other->ref_counts_[i] = ref_counts_[i];
+    }
+  }
 
  private:
   int ref_counts_[kNumRegisters];
 
   // Very fast inlined loop to find a free register.
   // Used in RegisterAllocator::AllocateWithoutSpilling.
   // Returns kNumRegisters if no free register found.
   inline int ScanForFreeRegister() {
     int i = 0;
     for (; i < kNumRegisters ; ++i) {
@@ skipping 74 matching lines @@
   }
 
  private:
   CodeGenerator* cgen_;
   RegisterFile registers_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_REGISTER_ALLOCATOR_H_