This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Altivec Linux support in GCC



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


Aldy Hernandez wrote:

"Michel" == Michel LESPINASSE <walken at zoy dot 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


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]