On Wed, May 15, 2013 at 02:58:22PM +0200, Richard Biener wrote:
> On Wed, May 15, 2013 at 2:07 PM, Marek Polacek <pola...@redhat.com> wrote:
> > /* Replace the uses of the name. */
> > if (name != ev)
> > - replace_uses_by (name, ev);
> > + {
> > + replace_uses_by (name, ev);
> > + if (dump_file && (dump_flags & TDF_SCEV))
>
> should be without dump_flags checking
Ok.
> > + {
> > + fprintf (dump_file, "(replace_stmt \n (");
> > + print_generic_expr (dump_file, name, 0);
> > + fprintf (dump_file, " with ");
> > + print_generic_expr (dump_file, ev, 0);
> > + fprintf (dump_file, ")\n) \n");
>
> and no need to do it the LISP-y way ;)
Good, I didn't like it much anyway.
> I would have liked to see failed attempts as well, then with TDF_DETAILS.
> Failed attempts for the "real" final value replacement stuff (I'm not sure
> the constant propagation part is worth keeping ... how often does it trigger?)
Not much often: I've measured it and it happens only in ~150 testcases
from the whole c/c++/fortran testsuites. So, like this? Thanks,
It looks like:
not replacing:
n_4 = PHI <n_3(4)>
and
final value replacement:
n_4 = PHI <n_3(4)>
with
n_4 = _1 + _12;
2013-05-15 Marek Polacek <pola...@redhat.com>
* tree-scalar-evolution.c (scev_const_prop): Add more dumps.
--- gcc/tree-scalar-evolution.c.mp 2013-05-15 15:09:06.579122696 +0200
+++ gcc/tree-scalar-evolution.c 2013-05-15 16:32:11.569217537 +0200
@@ -3385,12 +3385,24 @@ scev_const_prop (void)
to be turned into n %= 45. */
|| expression_expensive_p (def))
{
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "not replacing:\n ");
+ print_gimple_stmt (dump_file, phi, 0, 0);
+ fprintf (dump_file, "\n");
+ }
gsi_next (&psi);
continue;
}
/* Eliminate the PHI node and replace it by a computation outside
the loop. */
+ if (dump_file)
+ {
+ fprintf (dump_file, "\nfinal value replacement:\n ");
+ print_gimple_stmt (dump_file, phi, 0, 0);
+ fprintf (dump_file, " with\n ");
+ }
def = unshare_expr (def);
remove_phi_node (&psi, false);
@@ -3398,6 +3410,11 @@ scev_const_prop (void)
true, GSI_SAME_STMT);
ass = gimple_build_assign (rslt, def);
gsi_insert_before (&bsi, ass, GSI_SAME_STMT);
+ if (dump_file)
+ {
+ print_gimple_stmt (dump_file, ass, 0, 0);
+ fprintf (dump_file, "\n");
+ }
}
}
return 0;
Marek
