--- /dev/null
+/* { dg-do compile } */
+/* { dg-require-effective-target section_anchors } */
+/* { dg-require-effective-target vect_int } */
+
+#define N 32
+
+/* Increase alignment of struct if an array's offset is multiple of alignment of
+ vector type corresponding to it's scalar type.
+ For the below test-case:
+ offsetof(e) == 8 bytes.
+ i) For arm: let x = alignment of vector type corresponding to int,
+ x == 8 bytes.
+ Since offsetof(e) % x == 0, set DECL_ALIGN(a, b, c) to x.
+ ii) For aarch64, ppc: x == 16 bytes.
+ Since offsetof(e) % x != 0, don't increase alignment of a, b, c.
+*/
+
+static struct A {
+ int p1, p2;
+ int e[N];
+} a, b, c;
+
+int foo(void)
+{
+ for (int i = 0; i < N; i++)
+ a.e[i] = b.e[i] + c.e[i];
+
+ return a.e[0];
+}
+
+/* { dg-final { scan-ipa-dump-times "Increasing alignment of decl" 0 "increase_alignment" { target aarch64*-*-* } } } */
+/* { dg-final { scan-ipa-dump-times "Increasing alignment of decl" 0 "increase_alignment" { target powerpc64*-*-* } } } */
+/* { dg-final { scan-ipa-dump-times "Increasing alignment of decl" 3 "increase_alignment" { target arm*-*-* } } } */
This should involve global alignment analysis and in the future also
array padding. */
+static unsigned get_vec_alignment_for_type (tree);
+static hash_map<tree, unsigned> *type_align_map;
+
+/* Return alignment of array's vector type corresponding to scalar type.
+ 0 if no vector type exists. */
+static unsigned
+get_vec_alignment_for_array_type (tree type)
+{
+ gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
+
+ tree vectype = get_vectype_for_scalar_type (strip_array_types (type));
+ if (!vectype
+ || !TYPE_SIZE (type)
+ || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
+ || tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (vectype)))
+ return 0;
+
+ return TYPE_ALIGN (vectype);
+}
+
+/* Return alignment of field having maximum alignment of vector type
+ corresponding to it's scalar type. For now, we only consider fields whose
+ offset is a multiple of it's vector alignment.
+ 0 if no suitable field is found. */
+static unsigned
+get_vec_alignment_for_record_type (tree type)
+{
+ gcc_assert (TREE_CODE (type) == RECORD_TYPE);
+
+ unsigned max_align = 0, alignment;
+ HOST_WIDE_INT offset;
+ tree offset_tree;
+
+ if (TYPE_PACKED (type))
+ return 0;
+
+ unsigned *slot = type_align_map->get (type);
+ if (slot)
+ return *slot;
+
+ for (tree field = first_field (type);
+ field != NULL_TREE;
+ field = DECL_CHAIN (field))
+ {
+ /* Skip if not FIELD_DECL or if alignment is set by user. */
+ if (TREE_CODE (field) != FIELD_DECL
+ || DECL_USER_ALIGN (field)
+ || DECL_ARTIFICIAL (field))
+ continue;
+
+ /* We don't need to process the type further if offset is variable,
+ since the offsets of remaining members will also be variable. */
+ if (TREE_CODE (DECL_FIELD_OFFSET (field)) != INTEGER_CST
+ || TREE_CODE (DECL_FIELD_BIT_OFFSET (field)) != INTEGER_CST)
+ break;
+
+ /* Similarly stop processing the type if offset_tree
+ does not fit in unsigned HOST_WIDE_INT. */
+ offset_tree = bit_position (field);
+ if (!tree_fits_uhwi_p (offset_tree))
+ break;
+
+ offset = tree_to_uhwi (offset_tree);
+ alignment = get_vec_alignment_for_type (TREE_TYPE (field));
+
+ /* Get maximum alignment of vectorized field/array among those members
+ whose offset is multiple of the vector alignment. */
+ if (alignment
+ && (offset % alignment == 0)
+ && (alignment > max_align))
+ max_align = alignment;
+ }
+
+ type_align_map->put (type, max_align);
+ return max_align;
+}
+
+/* Return alignment of vector type corresponding to decl's scalar type
+ or 0 if it doesn't exist or the vector alignment is lesser than
+ decl's alignment. */
+static unsigned
+get_vec_alignment_for_type (tree type)
+{
+ if (type == NULL_TREE)
+ return 0;
+
+ gcc_assert (TYPE_P (type));
+
+ static unsigned alignment = 0;
+ switch (TREE_CODE (type))
+ {
+ case ARRAY_TYPE:
+ alignment = get_vec_alignment_for_array_type (type);
+ break;
+ case RECORD_TYPE:
+ alignment = get_vec_alignment_for_record_type (type);
+ break;
+ default:
+ alignment = 0;
+ break;
+ }
+
+ return (alignment > TYPE_ALIGN (type)) ? alignment : 0;
+}
+
+/* Entry point to increase_alignment pass. */
static unsigned int
increase_alignment (void)
{
varpool_node *vnode;
vect_location = UNKNOWN_LOCATION;
+ type_align_map = new hash_map<tree, unsigned>;
/* Increase the alignment of all global arrays for vectorization. */
FOR_EACH_DEFINED_VARIABLE (vnode)
{
- tree vectype, decl = vnode->decl;
- tree t;
+ tree decl = vnode->decl;
unsigned int alignment;
- t = TREE_TYPE (decl);
- if (TREE_CODE (t) != ARRAY_TYPE)
- continue;
- vectype = get_vectype_for_scalar_type (strip_array_types (t));
- if (!vectype)
- continue;
- alignment = TYPE_ALIGN (vectype);
- if (DECL_ALIGN (decl) >= alignment)
- continue;
-
- if (vect_can_force_dr_alignment_p (decl, alignment))
+ if ((decl_in_symtab_p (decl)
+ && !symtab_node::get (decl)->can_increase_alignment_p ())
+ || DECL_USER_ALIGN (decl) || DECL_ARTIFICIAL (decl))
+ continue;
+
+ alignment = get_vec_alignment_for_type (TREE_TYPE (decl));
+ if (alignment && vect_can_force_dr_alignment_p (decl, alignment))
{
- vnode->increase_alignment (TYPE_ALIGN (vectype));
+ vnode->increase_alignment (alignment);
dump_printf (MSG_NOTE, "Increasing alignment of decl: ");
dump_generic_expr (MSG_NOTE, TDF_SLIM, decl);
dump_printf (MSG_NOTE, "\n");
}
}
+
+ delete type_align_map;
return 0;
}
projects / platform / upstream / linaro-gcc.git / commitdiff