[cfe-dev] improved vector bool/pixel support

Anton Yartsev anton.yartsev at gmail.com
Tue Jul 20 20:11:09 PDT 2010


> On Jul 6, 2010, at 1:46 PM, Douglas Gregor wrote:
>
>    
>>> I'm happy to defer to Doug's opinion here.  However, I thought that the idea of a canonical type was that it represent the structural behavior of the type.  Semantically there should be no difference between the sugared and desugared type.  If "altivec" vectors have more behavior than just how they print, I don't think it's just sugar, right?
>>>        
>>
>> Do AltiVec vectors have more/different behavior from than GCC vectors? I honestly don't know. If they do, they need their own canonical types and we'll need to introduce appropriate implicit conversions between the two kinds of vectors. If the behavior is the same, then it's just sugar.
>>      
> Yes, they do.  For example,
>
> my_altivec_vector x = {1} does a splat, not a zero fill.
>
> -Chris
As I understand the conclusion is that AltiVec vectors need their own 
canonical type. So resending you the updated patch for review. The patch 
gives unique canonical type for AltiVec vectors and adds compatibility 
checking.

-- 
Anton

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