Altivec Linux support in GCC

[Kumar Gala]

On Tuesday, April 15, 2003, at 01:08 PM, Stan Shebs wrote:

> Aldy Hernandez wrote:
>
>>>>>>> "Michel" == Michel LESPINASSE <walken@zoy.org> writes:
>>>>>>>
>>
>>  > On Mon, Apr 14, 2003 at 12:49:48PM -0500, Kumar Gala wrote:
>> >> 1. What are there two options to enable the support? (-maltivec >> 
>> -mabi=altivec).  If I have a Linux PPC targeted GCC why do I need to 
>> >> tell it to use the abi to get altivec code generation?  This just 
>> seems >> confusing to the user (I dont have to specify the abi for 
>> any other >> option).
>>
>> Still, only the minority of users do this.
>>
>> I agree with y'all that -maltivec without -mabi=altivec is useful,
>> what I have argued for in the past (and again now), is having
>> -maltivec imply -mabi=altivec as the default.  Then, if you want the
>> functionality you describe, use -maltivec -mabi=no-altivec.
>>
> Sounds like a good idea.  I think when this all originally went in,
> we were being cautious and incremental - -maltivec would always work,
> but -mabi=altivec required cooperating libraries and such.  However,
> I think we're past that initial phase now!
>
> Apple goes one further actually, forces AltiVec-friendly ABI always,
> since system can trash you if you try to use AltiVec ops but not
> the proper ABI.

I guess this is my concern, especially with -mabi=no-altivec not being 
very well specified to the user.  It is not clear at all as to what a 
user gets with this option as far as AltiVec support goes.

- kumar