------- Comment #17 from rguenther at suse dot de 2008-09-22 11:14 -------
Subject: Re: [4.4 Regression] Revision 140257 causes
vectorizer tests failures
On Mon, 22 Sep 2008, irar at il dot ibm dot com wrote:
> ------- Comment #16 from irar at il dot ibm dot com 2008-09-22 10:33 -------
> (In reply to comment #15)
> > This is because the original access is through a restricted pointer, so the
> > check is conservatively correct at this point. We can move it to the
> > point where the vector pointer is created
>
> But this way we move the check to the transformation and we don't have a
> mechanism to stop in the middle of transformation.
Right, but if we correctly base the vectorized access on the scalar
one we never should fail this test (so I made it an assert - though
logically inverted :().
WRT vect_create_data_ref_ptr not only we have to build a correctly
restrict qualified type but also the decl (vect_get_new_vect_var)
needs to have its DECL_POINTER_ALIAS_SET set correctly.
So, like the following (which seems to work on x86_64, but it looks
like all the testcases with restricted pointers are not supported on
x86_64).
Index: gcc/tree-vect-transform.c
===================================================================
*** gcc/tree-vect-transform.c (revision 140544)
--- gcc/tree-vect-transform.c (working copy)
*************** vect_create_data_ref_ptr (gimple stmt, s
*** 1077,1084 ****
--- 1077,1095 ----
else
vect_ptr_type = build_pointer_type (vectype);
+ if (TREE_CODE (DR_BASE_ADDRESS (dr)) == SSA_NAME
+ && TYPE_RESTRICT (TREE_TYPE (DR_BASE_ADDRESS (dr))))
+ vect_ptr_type = build_qualified_type (vect_ptr_type, TYPE_QUAL_RESTRICT);
vect_ptr = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var,
get_name (base_name));
+ if (TREE_CODE (DR_BASE_ADDRESS (dr)) == SSA_NAME
+ && TYPE_RESTRICT (TREE_TYPE (DR_BASE_ADDRESS (dr))))
+ {
+ get_alias_set (base_name);
+ DECL_POINTER_ALIAS_SET (vect_ptr)
+ = DECL_POINTER_ALIAS_SET (SSA_NAME_VAR (DR_BASE_ADDRESS (dr)));
+ }
+
add_referenced_var (vect_ptr);
/** (2) Add aliasing information to the new vector-pointer:
*************** vectorizable_load (gimple stmt, gimple_s
*** 6388,6404 ****
return false;
}
- /* If accesses through a pointer to vectype do not alias the original
- memory reference we have a problem. This should never happen. */
- if (get_alias_set (vectype) != get_alias_set (gimple_assign_rhs1 (stmt))
- && !alias_set_subset_of (get_alias_set (vectype),
- get_alias_set (gimple_assign_rhs1 (stmt))))
- {
- if (vect_print_dump_info (REPORT_DETAILS))
- fprintf (vect_dump, "??? vector type does not alias scalar type");
- return false;
- }
-
/* The vector component type needs to be trivially convertible to the
scalar lhs. This should always be the case. */
if (!useless_type_conversion_p (TREE_TYPE (scalar_dest), TREE_TYPE
(vectype)))
--- 6399,6404 ----
*************** vectorizable_load (gimple stmt, gimple_s
*** 6662,6667 ****
--- 6662,6672 ----
default:
gcc_unreachable ();
}
+ /* If accesses through a pointer to vectype do not alias the original
+ memory reference we have a problem. This should never happen. */
+ gcc_assert (get_alias_set (data_ref) == get_alias_set
(gimple_assign_rhs1 (stmt))
+ || alias_set_subset_of (get_alias_set (data_ref),
+ get_alias_set (gimple_assign_rhs1
(stmt))));
vec_dest = vect_create_destination_var (scalar_dest, vectype);
new_stmt = gimple_build_assign (vec_dest, data_ref);
new_temp = make_ssa_name (vec_dest, new_stmt);
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37491
