The following fixes PR81573.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2017-07-27 Richard Biener <rguent...@suse.de>
PR tree-optimization/81573
PR tree-optimization/81494
* tree-vect-loop.c (vect_create_epilog_for_reduction): Handle
multi defuse cycle case.
* gcc.dg/torture/pr81573.c: New testcase.
Index: gcc/tree-vect-loop.c
===================================================================
--- gcc/tree-vect-loop.c (revision 250607)
+++ gcc/tree-vect-loop.c (working copy)
@@ -4787,20 +4800,17 @@ vect_create_epilog_for_reduction (vec<tr
if (GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)))
{
tree first_vect = PHI_RESULT (new_phis[0]);
- tree tmp;
gassign *new_vec_stmt = NULL;
-
vec_dest = vect_create_destination_var (scalar_dest, vectype);
for (k = 1; k < new_phis.length (); k++)
{
gimple *next_phi = new_phis[k];
tree second_vect = PHI_RESULT (next_phi);
-
- tmp = build2 (code, vectype, first_vect, second_vect);
- new_vec_stmt = gimple_build_assign (vec_dest, tmp);
- first_vect = make_ssa_name (vec_dest, new_vec_stmt);
- gimple_assign_set_lhs (new_vec_stmt, first_vect);
+ tree tem = make_ssa_name (vec_dest, new_vec_stmt);
+ new_vec_stmt = gimple_build_assign (tem, code,
+ first_vect, second_vect);
gsi_insert_before (&exit_gsi, new_vec_stmt, GSI_SAME_STMT);
+ first_vect = tem;
}
new_phi_result = first_vect;
@@ -4810,6 +4820,28 @@ vect_create_epilog_for_reduction (vec<tr
new_phis.safe_push (new_vec_stmt);
}
}
+ /* Likewise if we couldn't use a single defuse cycle. */
+ else if (ncopies > 1)
+ {
+ gcc_assert (new_phis.length () == 1);
+ tree first_vect = PHI_RESULT (new_phis[0]);
+ gassign *new_vec_stmt = NULL;
+ vec_dest = vect_create_destination_var (scalar_dest, vectype);
+ gimple *next_phi = new_phis[0];
+ for (int k = 1; k < ncopies; ++k)
+ {
+ next_phi = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (next_phi));
+ tree second_vect = PHI_RESULT (next_phi);
+ tree tem = make_ssa_name (vec_dest, new_vec_stmt);
+ new_vec_stmt = gimple_build_assign (tem, code,
+ first_vect, second_vect);
+ gsi_insert_before (&exit_gsi, new_vec_stmt, GSI_SAME_STMT);
+ first_vect = tem;
+ }
+ new_phi_result = first_vect;
+ new_phis.truncate (0);
+ new_phis.safe_push (new_vec_stmt);
+ }
else
new_phi_result = PHI_RESULT (new_phis[0]);
Index: gcc/testsuite/gcc.dg/torture/pr81573.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr81573.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr81573.c (working copy)
@@ -0,0 +1,16 @@
+/* { dg-do run } */
+
+int a = 1, *c = &a, d;
+char b;
+
+int main ()
+{
+ for (; b > -27; b--)
+ {
+ *c ^= b;
+ *c ^= 1;
+ }
+ while (a > 1)
+ ;
+ return 0;
+}
