poly_int: fold_ctor_reference

This patch changes the offset and size arguments to
fold_ctor_reference from unsigned HOST_WIDE_INT to poly_uint64.

2017-12-20  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* gimple-fold.h (fold_ctor_reference): Take the offset and size
	as poly_uint64 rather than unsigned HOST_WIDE_INT.
	* gimple-fold.c (fold_ctor_reference): Likewise.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r255869

gcc/ChangeLog

@@ -2,6 +2,14 @@
 	    Alan Hayward  <alan.hayward@arm.com>
 	    David Sherwood  <david.sherwood@arm.com>
 
+	* gimple-fold.h (fold_ctor_reference): Take the offset and size
+	as poly_uint64 rather than unsigned HOST_WIDE_INT.
+	* gimple-fold.c (fold_ctor_reference): Likewise.
+
+2017-12-20  Richard Sandiford  <richard.sandiford@linaro.org>
+	    Alan Hayward  <alan.hayward@arm.com>
+	    David Sherwood  <david.sherwood@arm.com>
+
 	* target.def (dwarf_poly_indeterminate_value): New hook.
 	* targhooks.h (default_dwarf_poly_indeterminate_value): Declare.
 	* targhooks.c (default_dwarf_poly_indeterminate_value): New function.

gcc/gimple-fold.c

@@ -6527,20 +6527,25 @@ fold_nonarray_ctor_reference (tree type, tree ctor,
   return build_zero_cst (type);
 }
 
-/* CTOR is value initializing memory, fold reference of type TYPE and size SIZE
-   to the memory at bit OFFSET.  */
+/* CTOR is value initializing memory, fold reference of type TYPE and
+   size POLY_SIZE to the memory at bit POLY_OFFSET.  */
 
 tree
-fold_ctor_reference (tree type, tree ctor, unsigned HOST_WIDE_INT offset,
-		     unsigned HOST_WIDE_INT size, tree from_decl)
+fold_ctor_reference (tree type, tree ctor, poly_uint64 poly_offset,
+		     poly_uint64 poly_size, tree from_decl)
 {
   tree ret;
 
   /* We found the field with exact match.  */
   if (useless_type_conversion_p (type, TREE_TYPE (ctor))
-      && !offset)
+      && known_eq (poly_offset, 0U))
     return canonicalize_constructor_val (unshare_expr (ctor), from_decl);
 
+  /* The remaining optimizations need a constant size and offset.  */
+  unsigned HOST_WIDE_INT size, offset;
+  if (!poly_size.is_constant (&size) || !poly_offset.is_constant (&offset))
+    return NULL_TREE;
+
   /* We are at the end of walk, see if we can view convert the
      result.  */
   if (!AGGREGATE_TYPE_P (TREE_TYPE (ctor)) && !offset

gcc/gimple-fold.h

@@ -44,8 +44,7 @@ extern tree follow_single_use_edges (tree);
 extern tree gimple_fold_stmt_to_constant_1 (gimple *, tree (*) (tree),
 					    tree (*) (tree) = no_follow_ssa_edges);
 extern tree gimple_fold_stmt_to_constant (gimple *, tree (*) (tree));
-extern tree fold_ctor_reference (tree, tree, unsigned HOST_WIDE_INT,
-				 unsigned HOST_WIDE_INT, tree);
+extern tree fold_ctor_reference (tree, tree, poly_uint64, poly_uint64, tree);
 extern tree fold_const_aggregate_ref_1 (tree, tree (*) (tree));
 extern tree fold_const_aggregate_ref (tree);
 extern tree gimple_get_virt_method_for_binfo (HOST_WIDE_INT, tree,