This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[PATCH] Fix up vectorizer cost model use of uninitialized value (PR tree-optimization/52210)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Richard Guenther <rguenther at suse dot de>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Mon, 13 Feb 2012 20:37:19 +0100
- Subject: [PATCH] Fix up vectorizer cost model use of uninitialized value (PR tree-optimization/52210)
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
The PR50912 changed vect_get_and_check_slp_defs dt from
array into scalar, which fails when calling vect_model_simple_cost
which looks at two array members. I believe even 4.6 checked just
the first operand, as it called it when processing the first operand,
so IMHO this patch doesn't regress (the very incomplete) cost model
handling and doesn't introduce undefined behavior.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2012-02-13 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/52210
* tree-vect-slp.c (vect_get_and_check_slp_defs): Call
vect_model_simple_cost with two entry vect_def_type array instead
of an address of dt.
* gcc.dg/pr52210.c: New test.
--- gcc/tree-vect-slp.c.jj 2012-02-07 16:05:51.000000000 +0100
+++ gcc/tree-vect-slp.c 2012-02-13 10:14:28.017357662 +0100
@@ -321,10 +321,15 @@ vect_get_and_check_slp_defs (loop_vec_in
vect_model_store_cost (stmt_info, ncopies_for_cost, false,
dt, slp_node);
else
- /* Not memory operation (we don't call this function for
- loads). */
- vect_model_simple_cost (stmt_info, ncopies_for_cost, &dt,
- slp_node);
+ {
+ enum vect_def_type dts[2];
+ dts[0] = dt;
+ dts[1] = vect_uninitialized_def;
+ /* Not memory operation (we don't call this function for
+ loads). */
+ vect_model_simple_cost (stmt_info, ncopies_for_cost, dts,
+ slp_node);
+ }
}
}
else
--- gcc/testsuite/gcc.dg/pr52210.c.jj 2012-02-13 10:27:46.692809216 +0100
+++ gcc/testsuite/gcc.dg/pr52210.c 2012-02-13 10:25:31.000000000 +0100
@@ -0,0 +1,12 @@
+/* PR tree-optimization/52210 */
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+void
+foo (long *x, long y, long z)
+{
+ long a = x[0];
+ long b = x[1];
+ x[0] = a & ~y;
+ x[1] = b & ~z;
+}
Jakub