Re: "Universal Binaries"

[Bob Friesenhahn]

On Thu, 16 Feb 2006, David Fang wrote:
>         For discussion reference, the recipe(s) for manually configuring a
> universal binary can be found here:
>
> http://developer.apple.com/technotes/tn2005/tn2137.html
>
>         There you can see a few ways of achieving the same result.  To get
> around the problem of autoconf tests being applicable to one CPU, one
> might be better off doing two single-arch builds (VPATH), and merging the
> results with lipo.
>         I haven't tried this myself, but some others have reported
> success.  I'm not sure why this 'defeats' autoconf.  It does introduce a

What I mean by 'defeats' autoconf is that the autoconf paradigm 
expects that the results of tests match what the final build will see. 
If both Intel and PPC code are compiled simultaneously based on the 
same configuration header, then there will be issues due to endianness 
and other aspects.  It is possible to write software which is not 
subject to these issues, but it is by using preprocessor defines 
provided by the compiler/system and is not the autoconf way.

Merging two different builds would be fine though.

Bob
======================================
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/