--- a/gcc/tree-into-ssa.c	Fri Oct 27 22:46:09 2017 +0900
+++ b/gcc/tree-into-ssa.c	Thu Oct 25 07:37:49 2018 +0900
@@ -1,5 +1,5 @@
 /* Rewrite a program in Normal form into SSA.
-   Copyright (C) 2001-2017 Free Software Foundation, Inc.
+   Copyright (C) 2001-2018 Free Software Foundation, Inc.
    Contributed by Diego Novillo <dnovillo@redhat.com>
 
 This file is part of GCC.
@@ -1463,7 +1463,8 @@
 class rewrite_dom_walker : public dom_walker
 {
 public:
-  rewrite_dom_walker (cdi_direction direction) : dom_walker (direction) {}
+  rewrite_dom_walker (cdi_direction direction)
+    : dom_walker (direction, ALL_BLOCKS, NULL) {}
 
   virtual edge before_dom_children (basic_block);
   virtual void after_dom_children (basic_block);
@@ -2153,7 +2154,8 @@
 class rewrite_update_dom_walker : public dom_walker
 {
 public:
-  rewrite_update_dom_walker (cdi_direction direction) : dom_walker (direction) {}
+  rewrite_update_dom_walker (cdi_direction direction)
+    : dom_walker (direction, ALL_BLOCKS, NULL) {}
 
   virtual edge before_dom_children (basic_block);
   virtual void after_dom_children (basic_block);
@@ -2322,7 +2324,7 @@
 };
 
 mark_def_dom_walker::mark_def_dom_walker (cdi_direction direction)
-  : dom_walker (direction), m_kills (BITMAP_ALLOC (NULL))
+  : dom_walker (direction, ALL_BLOCKS, NULL), m_kills (BITMAP_ALLOC (NULL))
 {
 }
 
@@ -2488,6 +2490,28 @@
 	SET_SSA_NAME_VAR_OR_IDENTIFIER (name, DECL_NAME (decl));
     }
 
+  /* Initialize SSA_NAME_POINTS_TO_READONLY_MEMORY.  */
+  tree fnspec = lookup_attribute ("fn spec",
+				  TYPE_ATTRIBUTES (TREE_TYPE (fun->decl)));
+  if (fnspec)
+    {
+      fnspec = TREE_VALUE (TREE_VALUE (fnspec));
+      unsigned i = 1;
+      for (tree arg = DECL_ARGUMENTS (cfun->decl);
+	   arg; arg = DECL_CHAIN (arg), ++i)
+	{
+	  if (i >= (unsigned) TREE_STRING_LENGTH (fnspec))
+	    break;
+	  if (TREE_STRING_POINTER (fnspec)[i]  == 'R'
+	      || TREE_STRING_POINTER (fnspec)[i] == 'r')
+	    {
+	      tree name = ssa_default_def (fun, arg);
+	      if (name)
+		SSA_NAME_POINTS_TO_READONLY_MEMORY (name) = 1;
+	    }
+	}
+    }
+
   return 0;
 }