Re: [TESTCASE] Minimized testcase for AltiVec segfault

[Aldy Hernandez <aldyh at redhat dot com>]

On Thursday, February 28, 2002, at 09:58  AM, Daniel Egger wrote:

> Am Mit, 2002-02-27 um 05.52 schrieb Aldy Hernandez:
>
>> second, it would probably better if you configured with 
>> --enable-altivec.
>> did you do that?  if so, you don't need to pass -maltivec or
>> -mabi=altivec.
>
> DOH! It does work with -mabi=altivec though you should really explain
> to me why it will affect address generation like this:

aha!  told you :)


> registers so they don't get clobbered. After all it still might be a bug
> which should be fixed.
>

it's a bit tricky.  i don't see any way of altivec working without
-mabi=altivec, but we couldn't just blindly modify the abi just because
we had altivec enabled, so we had to add another flag.

it is theoretically possible to use -maltivec without the altivec abi,
but that doesn't make much sense because you won't have VRSAVE set,
you won't get varargs (which are broken right now anyhow :-)) working,
you can't get the stack adjusted properly for the vector arguments,
etc etc.

i think -maltivec without the abi changes is there for somebody who
*really* knows what s/he's doing, has everything aligned properly, and
wants to have a function callable from non altivec compiled functions.

i guess... i can't see other reasons for it.  that's why 
--enable-altivec,
the proper blessed way of building an altivec toolchain, sets the abi
as well.

aldy