commit 113f925a58a37cb8f18cd9c7aeeb4c03f5fc6afe
Author: Jason Merrill <jason@redhat.com>
Date:   Tue Sep 13 08:46:06 2016 -0400

            * c-common.c (check_cxx_fundamental_alignment_constraints): Use
            unsigned HOST_WIDE_INT.

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 9b5e016..e3dc0f5 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -7861,8 +7861,9 @@ check_cxx_fundamental_alignment_constraints (tree node,
 					     int flags)
 {
   bool alignment_too_large_p = false;
-  unsigned requested_alignment = (1U << align_log) * BITS_PER_UNIT;
-  unsigned max_align = 0;
+  unsigned HOST_WIDE_INT requested_alignment
+    = (unsigned HOST_WIDE_INT)BITS_PER_UNIT << align_log;
+  unsigned HOST_WIDE_INT max_align = 0;
 
   if ((!(flags & ATTR_FLAG_CXX11) && !warn_cxx_compat)
       || (node == NULL_TREE || node == error_mark_node))
@@ -7910,14 +7911,15 @@ check_cxx_fundamental_alignment_constraints (tree node,
 	 largest alignment the object file can represent, but a type that is
 	 only allocated dynamically could request even larger alignment.  So
 	 only limit type alignment to what TYPE_ALIGN can represent.  */
-      if (requested_alignment > (max_align = 8U << 28))
+      if (requested_alignment > (max_align = (unsigned HOST_WIDE_INT)8 << 28))
 	alignment_too_large_p = true;
     }
 
   if (alignment_too_large_p)
     pedwarn (input_location, OPT_Wattributes,
 	     "requested alignment %d is larger than %d",
-	     requested_alignment / BITS_PER_UNIT, max_align / BITS_PER_UNIT);
+	     int(requested_alignment / BITS_PER_UNIT),
+	     int(max_align / BITS_PER_UNIT));
 
   return !alignment_too_large_p;
 }