Add a helper for getting the overall alignment of a DR

This combines the information from previous patches to give a guaranteed
alignment for the DR as a whole.  This should be a bit safer than using
base_element_aligned, since that only really took the base into account
(not the init or offset).

2017-07-03  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* tree-data-ref.h (dr_alignment): Declare.
	* tree-data-ref.c (dr_alignment): New function.
	* tree-vectorizer.h (dataref_aux): Remove base_element_aligned.
	* tree-vect-data-refs.c (vect_compute_data_ref_alignment): Don't
	set it.
	* tree-vect-stmts.c (vectorizable_store): Use dr_alignment.

From-SVN: r249917

1 files changed, 10 insertions, 0 deletions

diff --git a/gcc/tree-data-ref.h b/gcc/tree-data-ref.h
index 72c68d0..1559cd9 100644
--- a/gcc/tree-data-ref.h
+++ b/gcc/tree-data-ref.h
@@ -405,6 +405,16 @@ extern bool compute_all_dependences (vec<data_reference_p> ,
 				     vec<loop_p>, bool);
 extern tree find_data_references_in_bb (struct loop *, basic_block,
                                         vec<data_reference_p> *);
+extern unsigned int dr_alignment (innermost_loop_behavior *);
+
+/* Return the alignment in bytes that DR is guaranteed to have at all
+   times.  */
+
+inline unsigned int
+dr_alignment (data_reference *dr)
+{
+  return dr_alignment (&DR_INNERMOST (dr));
+}
 
 extern bool dr_may_alias_p (const struct data_reference *,
 			    const struct data_reference *, bool);