re PR tree-optimization/79256 (FAIL: gcc.dg/vect/pr25413a.c execution test)

2017-01-30  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/79256
	* targhooks.c (default_builtin_vector_alignment_reachable): Honor
	BIGGEST_FIELD_ALIGNMENT and ADJUST_FIELD_ALIGN to fix up bogus
	alignment on TYPE.
	* tree.c (build_aligned_type): Set TYPE_USER_ALIGN.

From-SVN: r245025

gcc/ChangeLog

+2017-01-30  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/79256
+	* targhooks.c (default_builtin_vector_alignment_reachable): Honor
+	BIGGEST_FIELD_ALIGNMENT and ADJUST_FIELD_ALIGN to fix up bogus
+	alignment on TYPE.
+	* tree.c (build_aligned_type): Set TYPE_USER_ALIGN.
+
 2017-01-30  Dominik Vogt  <vogt@linux.vnet.ibm.com>
 
 	PR target/79240

gcc/targhooks.c

@@ -1130,9 +1130,14 @@ default_vector_alignment (const_tree type)
 /* By default assume vectors of element TYPE require a multiple of the natural
    alignment of TYPE.  TYPE is naturally aligned if IS_PACKED is false.  */
 bool
-default_builtin_vector_alignment_reachable (const_tree /*type*/, bool is_packed)
+default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
 {
-  return ! is_packed;
+  if (is_packed)
+    return false;
+
+  /* If TYPE can be differently aligned in field context we have to punt
+     as TYPE may have wrong TYPE_ALIGN here (PR79278).  */
+  return min_align_of_type (CONST_CAST_TREE (type)) == TYPE_ALIGN_UNIT (type);
 }
 
 /* By default, assume that a target supports any factor of misalignment

gcc/tree.c

@@ -6684,6 +6684,7 @@ build_aligned_type (tree type, unsigned int align)
 
   t = build_variant_type_copy (type);
   SET_TYPE_ALIGN (t, align);
+  TYPE_USER_ALIGN (t) = 1;
 
   return t;
 }