[Bug tree-optimization/98845] [9/10/11/12 Regression] ICE: SSA corruption (Unable to coalesce ssa_names 2 and 23 which are marked as MUST COALESCE.) since r6-528-g465770e43996a132

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98845

--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Arseny Solokha from comment #11)
> It should be labeled [12 Regression] again, then, as the issue is still
> there on trunk.

 w/ -O2 -fno-tree-dce -fno-tree-dse (possibly with -fno-tree-dse also for the
testcase in the description)

int n;

__attribute__ ((returns_twice)) void
foo (void);

void
bar (void);

void
quux (int x)
{
  if (x)
    ++x;
  else
    {
      if (n)
        {
          x = 1;
          foo ();
        }
      else
        bar ();

      if (n)
        {
          ++x;
          ++n;
        }
    }
}