[PATCH] Optimize insertqi when we copy all the lower 64 bits.

[Rafael Avila de Espindola]

Sent from my iPhone

> On Apr 23, 2014, at 12:08, Nadav Rotem <nrotem at apple.com> wrote:
> 
> 
>> On Apr 23, 2014, at 6:56 AM, Rafael Espíndola <rafael.espindola at gmail.com> wrote:
>> 
>>> On 15 April 2014 14:04, Nadav Rotem <nrotem at apple.com> wrote:
>>> Hi Filipe,
>>> 
>>> Why is this an IR-level transform? Could you implement this in SelectionDAG ?
>> 
>> What is the advantage of doing this at SelectionDAG? Since this is an
>> intrinsic, we know all that we need at the IR level already. IR also
>> has the advantage of opening the potential for further optimizations
> It is not clear to me why we represent this intrinsic as an IR-level intrinsic and not as a regular insertelement instruction. We already have IR-level optimizations on insertelement and I prefer not to duplicate all of them. 
> 

That I fully agree with. If the operation can be represented with generic ir that is by far the best solution.


>> an has much better testing than SelecetionDAG.
>> 
>> Cheers,
>> Rafael
>