https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89725
--- Comment #7 from bin cheng <amker at gcc dot gnu.org> ---
I am testing below simple fix, it bypass access functions doesn't belong to
analyzing loop_nest:
diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c
index e536b463e96..410d44f43e8 100644
--- a/gcc/tree-data-ref.c
+++ b/gcc/tree-data-ref.c
@@ -4272,6 +4272,7 @@ build_classic_dist_vector_1 (struct
data_dependence_relation *ddr,
{
unsigned i;
lambda_vector init_v = lambda_vector_new (DDR_NB_LOOPS (ddr));
+ struct loop *loop = DDR_LOOP_NEST (ddr)[0];
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
{
@@ -4302,6 +4303,15 @@ build_classic_dist_vector_1 (struct
data_dependence_relation *ddr,
return false;
}
+ /* When data references are collected in a loop while data
+ dependences are analyzed in loop nest nested in the loop, we
+ would have more number of access functions than number of
+ loops. Skip access functions of loops not in the loop nest.
+
+ See PR89725 for more information. */
+ if (flow_loop_nested_p (get_loop (cfun, var_a), loop))
+ continue;
+
dist = int_cst_value (SUB_DISTANCE (subscript));
index = index_in_loop_nest (var_a, DDR_LOOP_NEST (ddr));
*index_carry = MIN (index, *index_carry);
Plus the assert in index_in_loop_nest.
