This is the mail archive of the
mailing list for the GCC project.
Re: [TESTCASE] Minimized testcase for AltiVec segfault
- From: Aldy Hernandez <aldyh at redhat dot com>
- To: Daniel Egger <degger at fhm dot edu>
- Cc: GCC Developer Mailinglist <gcc at gcc dot gnu dot org>
- Date: Thu, 28 Feb 2002 10:27:47 +1100
- Subject: Re: [TESTCASE] Minimized testcase for AltiVec segfault
>> 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: email@example.com
Professional Gypsy Lost in Australia
Red Hat, Inc.