Request for code review - (ZEE patch : Redundant Zero extension elimination)

[Jie Zhang]

Hi Sriraman,

On 01/14/2010 03:55 AM, Sriraman Tallam wrote:
> Hi Richard,
>
> With regards to your comments in :
> http://gcc.gnu.org/ml/gcc/2009-12/msg00028.html
>
>>> " which also did something stupid like move the patch down into the i386 subdirectory. It'll never be applied in that form if I have anything to say on the subject, because obviously this is a generic sort of optimization."
>
> I moved it to i386 based on comments from Paolo and Richard Guenther.
> I really don't care where the patch goes and I was just doing what
> Paolo and Richard felt strongly about at that time about  this being
> very specific to x86 and using x86 patterns.
>
> We could come to a consensus on this and I am more than willing to
> move it back if necessary.
>
> Please let me know what you think,

I would like to see your patch to be extended to be a generic 
optimization pass. Apparently it is a x86_64 specific one now. I have 
request from Blackfin kernel developers to do similar optimizations, not 
only ZEE but also SEE. So I'm looking into both your proposed ZEE patch 
and the already removed SEE pass. Your ZEE patch needs generalization. 
The SEE pass needs many nontrivial fixes. I have not decided which way 
to go.


Jie