--target=powerpc64-linux_altivec: Use rs6000_linux64_override_options()?

[Jan-Benedict Glaw]

Hi!

On Fri, 2022-10-28 14:19:10 -0500, Segher Boessenkool <segher@kernel.crashing.org> wrote:
> On Fri, Oct 28, 2022 at 07:34:24PM +0200, Jan-Benedict Glaw wrote:
> > While checking my bot build logs, I noticed that GCC configured for
> > --target=powerpc64-linux_altivec will pull in linux64.h and
> > linuxaltivec.h .
> > 
> > linux64.h
> >   * Will "#define TARGET_USES_LINUX64_OPT 1" (to make static void
> >     rs6000_linux64_override_options() available in rs6000.cc).
> >   * Will "#define SUBSUBTARGET_OVERRIDE_OPTIONS" to use
> >     rs6000_linux64_override_options().
> > 
> > linuxaltivec.h OTOH
> >   * Will undef / "#define SUBSUBTARGET_OVERRIDE_OPTIONS  rs6000_altivec_abi = 1"
> >     and thus no longer use rs6000_linux64_override_options()
> >   * That triggers a warning (unused-function).
> > 
> > To silence that warning, should linuxaltivec.h undefine
> > TARGET_USES_LINUX64_OPT? Or set rs6000_altivec_abi=1 and call
> > rs6000_linux64_override_options()?
> 
> Why do you use powerpc64-linux_altivec?  This things (normally spelled
> with a dash, not and underscore, btw) was made for 32-bit targets.  It
> never has done anything useful for 64-bit targets, afaik?

Because it's listed in ./contrib/config-list.mk:

/var/cache/git/gcc [master] # make -f contrib/config-list.mk show | tr ' ' $'\n' | grep altivec
powerpc-eabisimaltivec
powerpc-eabialtivec
powerpc64-linux_altivec

> (And not for 32-bit targets either really, but that is another issue.)

It seems to be on the target list since the very beginning, when
config-list.mk was created by Joern Rennecke. So somebody cared about
this configuration I guess?

  If this configuration isn't ment to be used, we'd just drop it from
the list I guess.

MfG, JBG

-- 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
URL: <https://gcc.gnu.org/pipermail/gcc/attachments/20221028/6d27a0cf/attachment-0001.sig>