http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48124
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Blocks|52080 |
--- Comment #9 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-02-01
12:34:55 UTC ---
Simpler patch I am going to test. Let's hope the wreckage adjust_address
does to the to_rtx MEM (apart from setting its mode) is harmless.
Index: expr.c
===================================================================
--- expr.c (revision 183791)
+++ expr.c (working copy)
@@ -4705,6 +4705,21 @@ expand_assignment (tree to, tree from, b
to_rtx = adjust_address (to_rtx, mode1, 0);
else if (GET_MODE (to_rtx) == VOIDmode)
to_rtx = adjust_address (to_rtx, BLKmode, 0);
+ /* If the alignment of tem is larger than its size and we
+ are performing a bitfield access limit the mode we use
+ for the access to make sure we do not access the decl
+ beyond its end. See PR48124. */
+ else if (GET_MODE (to_rtx) == BLKmode
+ && mode1 == VOIDmode
+ && DECL_P (tem)
+ && TREE_CODE (DECL_SIZE (tem)) == INTEGER_CST
+ && TREE_INT_CST_LOW (DECL_SIZE (tem)) % DECL_ALIGN (tem))
+ {
+ mode1 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (tem))
+ % DECL_ALIGN (tem),
+ MODE_INT, 0);
+ to_rtx = adjust_address (to_rtx, mode1, 0);
+ }
}
if (offset != 0)
