[Bug c/55882] unaligned load/store : incorrect struct offset

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55882



--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> 2013-01-08 
15:54:46 UTC ---

Or more correct



Index: gcc/emit-rtl.c

===================================================================

--- gcc/emit-rtl.c      (revision 195014)

+++ gcc/emit-rtl.c      (working copy)

@@ -1839,7 +1839,12 @@ set_mem_attributes_minus_bitpos (rtx ref



       if (!align_computed)

        {

-         unsigned int obj_align = get_object_alignment (t);

+         unsigned int obj_align;

+         unsigned HOST_WIDE_INT obj_bitpos;

+         get_object_alignment_1 (t, &obj_align, &obj_bitpos);

+         obj_bitpos = (obj_bitpos + apply_bitpos) & (obj_align - 1);

+         if (obj_bitpos != 0)

+           obj_align = (obj_bitpos & -obj_bitpos);

          attrs.align = MAX (attrs.align, obj_align);

        }

     }