[PATCH, rs6000] Fix PR61542 - V4SF vector extract for little endian

[Bill Schmidt]

Bernd, thanks.  At this point I think I will avoid opening this can of
worms and not worry about backporting the test case.

Thanks,
Bill

On Wed, 2014-06-18 at 19:18 +0200, Bernd Edlinger wrote:
> Hi,
> 
> On Wed, 18 Jun 2014 09:56:15, David Edelsohn wrote:
> >
> > On Tue, Jun 17, 2014 at 6:44 PM, BIll Schmidt
> > <wschmidt@linux.vnet.ibm.com> wrote:
> >> Hi,
> >>
> >> As described in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61542, a
> >> new test case (gcc.dg/vect/vect-nop-move.c) was added in 4.9. This
> >> exposes a bug on PowerPC little endian for extracting an element from a
> >> V4SF value that goes back to 4.8. The following patch fixes the
> >> problem.
> >>
> >> Tested on powerpc64le-unknown-linux-gnu with no regressions. Ok to
> >> commit to trunk? I would also like to commit to 4.8 and 4.9 as soon as
> >> possible to be picked up by the distros.
> >
> > This is okay everywhere.
> >
> >> I would also like to backport gcc.dg/vect/vect-nop-move.c to 4.8 to
> >> provide regression coverage.
> >
> > You should ask Bernd and the RMs. Was the bug fix that prompted the
> > new testcase backported to all targets?
> >
> > Thanks, David
> 
> actually I only added the check_vect to that test case, but that
> exposed a bug on Solaris-9.
> 
> See https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=207668.
> 
> That was in the -fdump-rtl-combine-details handling, where
> fprintf got a NULL value passed for %s, which ICEs on Solaris9.
> 
> So if you backport that test case, be sure to check that one too.
> 
> Originally the test case seems to check something for the aarch64-target.
> See https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=205712.
> 
> Obviously the patch in  rtlanal.c (set_noop_p) was never backported to the 4.8 branch.
> Maybe Tejas who originally wrote that test case, can explain, if it makes
> sense to backport this fix too.
> 
> 
> Thanks
> Bernd.
>