https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123285
--- Comment #13 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #12)
> So I actually the problem is not anything except\ we don't process groupN[1]
> in some cases due to being the last alloc :). This means we don't mark the
> groups correctly.
Even prcoessing that does not fix the issue because the chain has been already
formed and we don't re-update the "color"'s candidates.
So the fix is move the clobber part before the forming of the chain.
And that simple fix gets what we want (for the simplified testcase):
```
Colors:
color 0:
chains:
0: r112[0] r115[0] r117[0]
1: r112[1] r116[0] r117[1]
FPR candidates: YYYYYYYY YYYYYYYY YYYYYYYY YYYYY---
FPR preferences:
```
