With get_object_alignment and get_object_or_type_alignment fused
it is now easy to fix PR53970 and remove the bogus
contains_packed_reference function. The vectorizer wants to know
whether the scalar access is aligned in a way that peeling
can eventually reach VF * scalar alignment (thus, vector alignment).
So, just ask that - whether the scalar access is aligned to at least
its size.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2012-07-18 Richard Guenther <rguent...@suse.de>
PR tree-optimization/53970
* tree.h (contains_packed_reference): Remove.
* expr.c (contains_packed_reference): Likewise.
* tree-vect-data-refs.c (not_size_aligned): New function.
(vector_alignment_reachable_p): Use it.
(vect_supportable_dr_alignment): Likewise.
* g++.dg/torture/pr53970.C: New testcase.
Index: gcc/tree.h
===================================================================
*** gcc/tree.h (revision 189607)
--- gcc/tree.h (working copy)
*************** extern tree get_inner_reference (tree, H
*** 5068,5079 ****
tree *, enum machine_mode *, int *, int *,
bool);
- /* Given an expression EXP that may be a COMPONENT_REF, an ARRAY_REF or an
- ARRAY_RANGE_REF, look for whether EXP or any nested component-refs within
- EXP is marked as PACKED. */
-
- extern bool contains_packed_reference (const_tree exp);
-
/* Return a tree of sizetype representing the size, in bytes, of the element
of EXP, an ARRAY_REF or an ARRAY_RANGE_REF. */
--- 5068,5073 ----
Index: gcc/expr.c
===================================================================
*** gcc/expr.c (revision 189607)
--- gcc/expr.c (working copy)
*************** get_inner_reference (tree exp, HOST_WIDE
*** 6709,6755 ****
return exp;
}
- /* Given an expression EXP that may be a COMPONENT_REF, an ARRAY_REF or an
- ARRAY_RANGE_REF, look for whether EXP or any nested component-refs within
- EXP is marked as PACKED. */
-
- bool
- contains_packed_reference (const_tree exp)
- {
- bool packed_p = false;
-
- while (1)
- {
- switch (TREE_CODE (exp))
- {
- case COMPONENT_REF:
- {
- tree field = TREE_OPERAND (exp, 1);
- packed_p = DECL_PACKED (field)
- || TYPE_PACKED (TREE_TYPE (field))
- || TYPE_PACKED (TREE_TYPE (exp));
- if (packed_p)
- goto done;
- }
- break;
-
- case BIT_FIELD_REF:
- case ARRAY_REF:
- case ARRAY_RANGE_REF:
- case REALPART_EXPR:
- case IMAGPART_EXPR:
- case VIEW_CONVERT_EXPR:
- break;
-
- default:
- goto done;
- }
- exp = TREE_OPERAND (exp, 0);
- }
- done:
- return packed_p;
- }
-
/* Return a tree of sizetype representing the size, in bytes, of the element
of EXP, an ARRAY_REF or an ARRAY_RANGE_REF. */
--- 6709,6714 ----
Index: gcc/tree-vect-data-refs.c
===================================================================
*** gcc/tree-vect-data-refs.c (revision 189607)
--- gcc/tree-vect-data-refs.c (working copy)
*************** vect_verify_datarefs_alignment (loop_vec
*** 1131,1136 ****
--- 1131,1148 ----
return true;
}
+ /* Given an memory reference EXP return whether its alignment is less
+ than its size. */
+
+ static bool
+ not_size_aligned (tree exp)
+ {
+ if (!host_integerp (TYPE_SIZE (TREE_TYPE (exp)), 1))
+ return true;
+
+ return (tree_low_cst (TYPE_SIZE (TREE_TYPE (exp)), 1)
+ > get_object_alignment (exp));
+ }
/* Function vector_alignment_reachable_p
*************** vector_alignment_reachable_p (struct dat
*** 1184,1195 ****
if (!known_alignment_for_access_p (dr))
{
! tree type = (TREE_TYPE (DR_REF (dr)));
! bool is_packed = contains_packed_reference (DR_REF (dr));
!
! if (compare_tree_int (TYPE_SIZE (type), TYPE_ALIGN (type)) > 0)
! is_packed = true;
!
if (vect_print_dump_info (REPORT_DETAILS))
fprintf (vect_dump, "Unknown misalignment, is_packed = %d",is_packed);
if (targetm.vectorize.vector_alignment_reachable (type, is_packed))
--- 1196,1203 ----
if (!known_alignment_for_access_p (dr))
{
! tree type = TREE_TYPE (DR_REF (dr));
! bool is_packed = not_size_aligned (DR_REF (dr));
if (vect_print_dump_info (REPORT_DETAILS))
fprintf (vect_dump, "Unknown misalignment, is_packed = %d",is_packed);
if (targetm.vectorize.vector_alignment_reachable (type, is_packed))
*************** vect_supportable_dr_alignment (struct da
*** 4863,4869 ****
return dr_explicit_realign_optimized;
}
if (!known_alignment_for_access_p (dr))
! is_packed = contains_packed_reference (DR_REF (dr));
if (targetm.vectorize.
support_vector_misalignment (mode, type,
--- 4871,4877 ----
return dr_explicit_realign_optimized;
}
if (!known_alignment_for_access_p (dr))
! is_packed = not_size_aligned (DR_REF (dr));
if (targetm.vectorize.
support_vector_misalignment (mode, type,
*************** vect_supportable_dr_alignment (struct da
*** 4877,4883 ****
tree type = (TREE_TYPE (DR_REF (dr)));
if (!known_alignment_for_access_p (dr))
! is_packed = contains_packed_reference (DR_REF (dr));
if (targetm.vectorize.
support_vector_misalignment (mode, type,
--- 4885,4891 ----
tree type = (TREE_TYPE (DR_REF (dr)));
if (!known_alignment_for_access_p (dr))
! is_packed = not_size_aligned (DR_REF (dr));
if (targetm.vectorize.
support_vector_misalignment (mode, type,
Index: gcc/testsuite/g++.dg/torture/pr53970.C
===================================================================
*** /dev/null 1970-01-01 00:00:00.000000000 +0000
--- gcc/testsuite/g++.dg/torture/pr53970.C 2012-07-16 14:30:04.831593896
+0200
***************
*** 0 ****
--- 1,17 ----
+ // { dg-do run }
+
+ #pragma pack(1)
+ struct mystruct {
+ char c;
+ unsigned long l[1024];
+ };
+ #pragma pack()
+
+ int main(int argc, char **argv)
+ {
+ mystruct *a = new mystruct;
+ unsigned long i;
+ for (i = 0; i < 1024; ++i)
+ a->l[i] = 0xdeadbeaf;
+ return 0;
+ }
