Re: [TESTCASE] Minimized testcase for AltiVec segfault

[Aldy Hernandez <aldyh at redhat dot com>]

>> 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.
>
> That would be me! I know what I'm doing, have no intention to pass
> vector arguments or use varargs.

how about local variables?  there are some magic alignment rules
that are keyed off of abi=altivec. ... especially the stack boundary.

how about vrsave?  surely you need vrsave to be set properly, otherwise
the OS will not save your vector registers on a context-switch.

how about the prologue and epilogue?  the altivec registers won't be
saved/restored unless abi=altivec.

some call used registers being altivec?

i guess you could use all global variables, and have the OS
save/restore all vector registers on a context switch (slooow).

these are just a few of the things that came up while poking around
the code (search for TARGET_ALTIVEC_ABI).

perhaps this needs to be readressed and having -maltivec imply an
abi change^Wenhancement.  i for one, wouldn't mind getting
rid of -mabi=altivec, but i believe geoff wanted it that way.

--
Aldy Hernandez                                E-mail: aldyh@redhat.com
Professional Gypsy Lost in Australia
Red Hat, Inc.