http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52395
--- Comment #6 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-02-27
10:25:49 UTC ---
If all was well ('base' is literally appearing in the IL before SRA / IPA-SRA)
we could do
Index: gcc/tree-sra.c
===================================================================
--- gcc/tree-sra.c (revision 184591)
+++ gcc/tree-sra.c (working copy)
@@ -1526,10 +1526,12 @@ build_ref_for_offset (location_t loc, tr
we can extract more optimistic alignment information
by looking at the access mode. That would constrain the
alignment of base + base_offset which we would need to
- adjust according to offset.
- ??? But it is not at all clear that prev_base is an access
- that was in the IL that way, so be conservative for now. */
+ adjust according to offset. */
align = get_pointer_alignment_1 (base, &misalign);
+ if (misalign == 0
+ && (TREE_CODE (prev_base) == MEM_REF
+ || TREE_CODE (prev_base) == TARGET_MEM_REF))
+ align = MAX (align, TYPE_ALIGN (TREE_TYPE (prev_base)));
misalign += (double_int_sext (tree_to_double_int (off),
TYPE_PRECISION (TREE_TYPE (off))).low
* BITS_PER_UNIT);
to mimic get_object_or_type_alignment.
At least for the ipa-cp.c use I _do_ know there is no such access.
