https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104440
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2022-02-08
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #5)
> (In reply to Tom de Vries from comment #4)
> > (In reply to Andrew Pinski from comment #2)
> > > I thought there was another bug that reported a similar issue.
> >
> > You mean related to nvptx, or in general?
>
> It was in general. PR 21111 is related but not the same issue.
>
>
> PR 61810 is the one pointing out the problems with init-regs and talking
> about removing it.
I think there's a bug that ifcombine produces the situation and that
valgrind complains about uninitialized uses.
Note that indeed the init-regs pass should go away.
It's somewhat unfeasible to compute a must-initialized regs so the issue
is really hard to avoid. But nobody tried yet (it would also come at a cost
of course). It would definitely inhibit all early short-circuiting on
GENERIC (a good thing, but with a lot of fallout I think).
That said, --param logical-op-non-short-circuit=0 is only a workaround until
you hit ifcombine doing similar transforms.
LOGICAL_OP_NON_SHORT_CIRCUIT is a target macro btw, so you could arrange it
to be zero for nvptx (but that's of course too late since the hosts
LOGICAL_OP_NON_SHORT_CIRCUIT value will be used).
