[PATCH][Peephole] Rewrite copies to avoid cross register banks copies.

[Quentin Colombet]

Hi Jakob,

Thanks for the review!

On Sep 12, 2013, at 12:34 PM, Jakob Stoklund Olesen <stoklund at 2pi.dk> wrote:

> 
> On Sep 12, 2013, at 11:32 AM, Quentin Colombet <qcolombet at apple.com> wrote:
> 
>> Hi Jakob,
>> 
>> Could you have a look to this patch, please?
>> 
>> Thanks,
>> Quentin
>> <PeepholeCopy.svndiff>
> 
> Hi Quentin,
> 
> The patch looks good, but it seems to be doing the same thing as optimizeBitcastInstr(), only better.
Agreed.

> Could those two be merged, or can we just get rid of ‘bit cast’ instructions now?
For now, I prefer merging because I think removing the 'bit cast' instructions should be part of a separate patch/discussion.

> 
> It seems to me that targets should simply emit cross-class COPY instructions instead of marking some native copy instructions as ‘bit casts’.
Agreed, I also think that the 'bit casts' instructions are redundant with cross-class COPY instructions and I would like to get rid of them for the sake of simplicity.

> 
> What do you think?
I will update the patch to merge the two functions and I will look at the 'bit cast' stuff to make another, separate proposal.

-Quentin

> 
> /jakob
>