OS::MemMove/OS::MemCopy: Don't call through to generated code when size == 0 to avoid prefetching i…

src/ia32/codegen-ia32.cc

 // 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 617 matching lines @@
   }
 
   __ bind(&pop_and_return);
   MemMoveEmitPopAndReturn(&masm);
 
   CodeDesc desc;
   masm.GetCode(&desc);
   ASSERT(!RelocInfo::RequiresRelocation(desc));
   CPU::FlushICache(buffer, actual_size);
   OS::ProtectCode(buffer, actual_size);
+  // TODO(jkummerow): It would be nice to register this code creation event
+  // with the PROFILE / GDBJIT system.
   return FUNCTION_CAST<OS::MemMoveFunction>(buffer);
 }
 
 
 #undef __
 
 // -------------------------------------------------------------------------
 // Code generators
 
 #define __ ACCESS_MASM(masm)
@@ skipping 566 matching lines @@
     Code* stub = GetCodeAgeStub(age, parity);
     CodePatcher patcher(sequence, young_length);
     patcher.masm()->call(stub->instruction_start(), RelocInfo::NONE32);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32