[cxx-abi-dev] mangling vector types

[David Vandevoorde]

On Nov 11, 2009, at 10:54 PM, Chris Lattner wrote:

>
> On Nov 11, 2009, at 1:56 PM, David Vandevoorde wrote:
>
>>
>> On Nov 11, 2009, at 4:35 PM, Jason Merrill wrote:
>>
>>> On 11/11/2009 04:33 PM, Jason Merrill wrote:
>>>>>> Dv <n_elements number> _ <element type>
>>>>
>>>> Though a plain /number/ there doesn't allow for template  
>>>> substitution.
>>>> Perhaps
>>>>
>>>> Dv _ <expression> _ <element type>
>>>>
>>>> when the number of elements is value-dependent?
>>
>>
>> Ah yes: That looks good.
>>
>>
>>> ...in which case we could go back to the log2 idea for the non- 
>>> dependent case.
>>
>>
>> I could go either way on that.  I suppose some day someone might  
>> decide to pack 5 24-bit integers in a 128-bit register, and then  
>> the log2 approach would require revision again (but that would be  
>> entirely feasible, I think).
>
> vectors of 3 elements are very common in the graphics world.  Clang  
> supports arbitrary width vectors, including bizarre things like 25- 
> wide float vectors etc.


I think that settles it then: A simple count instead of a log2 value.

	Daveed