Bug#971027: gcc-10: regression in 10.2.0-9 causes segmentation fault in vlc

[Richard Biener <rguenther@suse.de>]

On Wed, 30 Sep 2020, Ahzo wrote:

> 
> Sep 29, 2020, 07:14 by rguenther@suse.de:
> 
> > I've filed > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97236
> >
> > Someone needs to create a testcase or provide instructions how to
> > reproduce the bug.
> >
> 
> Thanks for taking care of this issue upstream.
> 
> Sep 29, 2020, 15:18 by doko@debian.org:
> 
> > On 9/29/20 12:30 PM, Matthias Klose wrote:
> > upstream now has a reduced test case.
> >
> > 10.2.0-12 is uploaded, reverting that commit for now.
> >
> Thanks for the quick upload. This should prevent further fallout, until upstream finds a better solution.

Note reverting just this rev will cause

long long x[24];
long long y[16];
long long z[8];

void __attribute__((noinline)) foo()
{
  for (int i = 0; i < 8; ++i)
    {
      y[2*i] = x[3*i];
      y[2*i + 1] = x[3*i + 1];
      z[i] = 1;
    }
}

to be miscompiled.  This in turn was triggered by the backport of
another fix, 1dbb919d0868319a5503b91049283a189ac1b4ac which I suggest
to revert as well then.