http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48172
--- Comment #12 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-12
12:46:10 UTC ---
Like this?
Index: gcc/tree-vect-loop-manip.c
===================================================================
--- gcc/tree-vect-loop-manip.c (revision 173703)
+++ gcc/tree-vect-loop-manip.c (working copy)
@@ -2353,23 +2353,19 @@ vect_create_cond_for_align_checks (loop_
Input:
DR: The data reference.
- VECT_FACTOR: vectorization factor.
- SCALAR_LOOP_NITERS: number of iterations.
+ LENGTH_FACTOR: segment length to consider.
Return an expression whose value is the size of segment which will be
accessed by DR. */
static tree
-vect_vfa_segment_size (struct data_reference *dr, int vect_factor,
+vect_vfa_segment_size (struct data_reference *dr, tree length_factor,
tree scalar_loop_niters)
{
tree segment_length;
segment_length = size_binop (MULT_EXPR,
fold_convert (sizetype, DR_STEP (dr)),
- size_int (vect_factor));
- segment_length = size_binop (MULT_EXPR,
- segment_length,
- fold_convert (sizetype, scalar_loop_niters));
+ fold_convert (sizetype, length_factor));
if (vect_supportable_dr_alignment (dr, false)
== dr_explicit_realign_optimized)
{
@@ -2465,10 +2461,12 @@ vect_create_cond_for_alias_checks (loop_
vect_create_addr_base_for_vector_ref (stmt_b, cond_expr_stmt_list,
NULL_TREE, loop);
- segment_length_a = vect_vfa_segment_size (dr_a, vect_factor,
- scalar_loop_iters);
- segment_length_b = vect_vfa_segment_size (dr_b, vect_factor,
- scalar_loop_iters);
+ if (!operand_equal_p (DR_STEP (dr_a), DR_STEP (dr_b), 0))
+ length_factor = scalar_loop_iters;
+ else
+ length_factor = size_int (vect_factor);
+ segment_length_a = vect_vfa_segment_size (dr_a, length_factor);
+ segment_length_b = vect_vfa_segment_size (dr_b, length_factor);
if (vect_print_dump_info (REPORT_DR_DETAILS))
{
I also think that the re-alignment adjustment needs to be multiplied
by DR_STEP (maybe we only support it for DR_STEP == 1 at the moment).
