Can register rename pass rename a callee-saved register?

[Mohamed Shafi]

2008/6/19 Ian Lance Taylor <iant@google.com>:
> "Mohamed Shafi" <shafitvm@gmail.com> writes:
>
>>> Which version of gcc?  I was under the impression that this
>>> longstanding buglet was cleaned up by the dataflow work.
>>>
>>
>>    I am doing a port in gcc 4.1.2. The register is actually replaced
>> by register copy-propagation optimization pass.
>
> I believe that in gcc 4.3 this unnecessary store and load should no
> longer happen.
>
   Can you tell me what was done in gcc 4.3 so that i can back port
the changes to gcc 4.1.2

Regards,
Shafi