Runtime Altivec detection

Nathan Ingersoll ningerso at
Sat Mar 8 05:08:02 EST 2003

On Fri, Mar 07, 2003 at 06:54:58PM +0000, Magnus Damm wrote:
> mplayer and ffmpeg does some kind of detection runtime.
> I'm playing with it right now actually.

Last I heard, it was a compile time detection or flag. So you had to build
separate binaries for your G4 and non-G4 machines.

> While at it:
> I've seen that -maltivec and -mabi=altivec is passed sometimes.
> If I want to build a binary that should be able to run on a
> G3 without altivec and utilize altivec when present on a G4,
> what flags should I use?

There is no specific flag for doing so, you need some code to detect the
capability, and then decide whether to use the Altivec routine.

| Nathan Ingersoll           \\ Computer Systems & Network Coordinator |
| ningerso at    \\            |
|   \\ Minnesota Center for Rural Health    |

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