This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: Implicit altivec vs. linux kernel build
On Sun, 2005-02-27 at 18:40 -0500, Andrew Pinski wrote:
> On Feb 27, 2005, at 6:35 PM, David Edelsohn wrote:
>
> > As Andrew Pinski mentioned, you also can use -mcpu=970
> > -mno-altivec. That should allow the assembler to accept Altivec
> > instructions, but GCC will not know about any Altivec registers for
> > inlined assembly parameters.
>
> As I and Ben found out that does not work, altivec is still turned on
> and there is no way to turn it off. Alan has a patch which he is going
> to post (again) on my request to fix the problem with "-mcpu=power4
> -maltivec",
> I don't know if -mno-altivec will work though.
Ok. What I need is -mcpu=power4 -maltivec
Later on, if we end up having another CPU with altivec for which we wish
to provide a specific -mcpu=<....> option for optimization, we'll have
to add -mno-altivec.
The issue then will be, can we have -mno-altivec in the main Makefile
CFLAGS and "override" this with -maltivec on a single file (the RAID6
code). The way the kernel makefiles work, this won't be simple unless
gcc can grok -mno-altivec -maltivec with the later overriding the
former...
Ben.