Re: GCC 4.3.0 Status Report (2008-02-14)

[Mark Mitchell <mark at codesourcery dot com>]

David Edelsohn wrote:

> 	The patch was suppose to enable -mabi=altivec when -maltivec is
> enabled, not change the default ABI.

OK.

If I understand correctly, then, this is going to be an ABI break for 
32-bit Power GNU/Linux users using an AltiVec CPU (like 970).  In 
particular, if I have code that I compiled with -mcpu=970 (and no other 
options) with GCC 4.2, it's not going to be link-compatible with code 
compiled in the same way for GCC 4.3.  Is that right?  Is that still 
true if I didn't use AltiVec extensions (whether via the AltiVec PEM 
syntax or via GCC's vector extensions)?  In other words, is "plain" C 
code going to be incompatible?

I understand that without making some kind of change things are just 
plain broken.  And, I'm not making a judgment as to the desirability of 
making a change, but I'd like to understand what we're doing and what 
impact it might have on the various stakeholders.

Thanks,

--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713