https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95493
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot
gnu.org
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
OK, so the issue is we're getting these MEM_ATTRs when expanding the base
as
(mem/c:V4SI (plus:DI (reg/f:DI 77 virtual-stack-vars)
(const_int -32 [0xffffffffffffffe0])) [5 MEM[(struct ._anon_0 *)_42]+0
S16 A128])
and set_mem_attributes_minus_bitpos due to the variable array-ref wouldn't
assign any here but inherits the already set ones.
/* Default values from pre-existing memory attributes if present. */
refattrs = MEM_ATTRS (ref);
if (refattrs)
{
/* ??? Can this ever happen? Calling this routine on a MEM that
already carries memory attributes should probably be invalid. */
attrs.expr = refattrs->expr;
attrs.offset_known_p = refattrs->offset_known_p;
attrs.offset = refattrs->offset;
attrs.size_known_p = refattrs->size_known_p;
attrs.size = refattrs->size;
attrs.align = refattrs->align;
}
so the following fixes the issue, the MEM_ATTRs are not what the code
expects them to be set with otherwise. Because clearly offset_known_p
should be false.
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index 2b790636366..0a72269e2ce 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -2114,6 +2114,10 @@ set_mem_attributes_minus_bitpos (rtx ref, tree t, int
objectp,
}
while (TREE_CODE (t2) == ARRAY_REF);
+ attrs.expr = NULL_TREE;
+ attrs.offset_known_p = false;
+ attrs.offset = 0;
+ apply_bitpos = 0;
if (DECL_P (t2)
|| (TREE_CODE (t2) == COMPONENT_REF
/* For trailing arrays t2 doesn't have a size that
