On Sun, 24 Jul 2011, Sebastian Pop wrote:
> On Sun, Jul 24, 2011 at 05:59, Richard Guenther
> <richard.guent...@gmail.com> wrote:
> > For two IVs with the same precision, one signed and one unsigned you choose
> > signedness of the canonical IV based on the random order of PHIs - that
> > doesn't
> > look correct.
> >
> > I think what you should do here is use an unsigned type if any of the IVs
> > with
> > the current max precision is unsigned.
>
> Attached is the updated patch. Bootstrapped and tested on amd64-linux.
> Ok for trunk?
for (psi = gsi_start_phis (loop->header);
!gsi_end_p (psi); gsi_next (&psi))
@@ -1207,11 +1209,25 @@ canonicalize_loop_ivs (struct loop *loop, tree
*nit,
bool bump_in_latch)
gimple phi = gsi_stmt (psi);
tree res = PHI_RESULT (phi);
- if (is_gimple_reg (res) && TYPE_PRECISION (TREE_TYPE (res)) >
precision)
- precision = TYPE_PRECISION (TREE_TYPE (res));
+ if (!is_gimple_reg (res))
+ continue;
+
+ type = TREE_TYPE (res);
+ if (TYPE_PRECISION (type) > precision)
+ {
+ precision = TYPE_PRECISION (type);
+ unsigned_p = TYPE_UNSIGNED (type);
+ continue;
+ }
+
+ if (TYPE_PRECISION (type) == precision
+ && TYPE_UNSIGNED (type))
+ unsigned_p = true;
}
I think we also need to care for non-integral PHIs where TYPE_PRECISION
and TYPE_UNSIGNED are not applicable (seems the original code is also
buggy here?). So, sth like
type = TREE_TYPE (res);
if (!is_gimple_reg (res)
|| !INTEGRAL_TYPE_P (type)
|| TYPE_PRECISION (type) < precision)
continue;
precision = TYPE_PRECISION (type);
unsigned_p |= TYPE_UNSIGNED (type);
}
would be ok.
Ok with that change.
Thanks,
Richard.
>
> Thanks,
> Sebastian
>
--
Richard Guenther <rguent...@suse.de>
Novell / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer
