--- a/gcc/tree-outof-ssa.c	Fri Oct 27 22:46:09 2017 +0900
+++ b/gcc/tree-outof-ssa.c	Thu Oct 25 07:37:49 2018 +0900
@@ -1,5 +1,5 @@
 /* Convert a program in SSA form into Normal form.
-   Copyright (C) 2004-2017 Free Software Foundation, Inc.
+   Copyright (C) 2004-2018 Free Software Foundation, Inc.
    Contributed by Andrew Macleod <amacleod@redhat.com>
 
 This file is part of GCC.
@@ -27,10 +27,12 @@
 #include "gimple.h"
 #include "cfghooks.h"
 #include "ssa.h"
+#include "tree-ssa.h"
 #include "memmodel.h"
 #include "emit-rtl.h"
 #include "gimple-pretty-print.h"
 #include "diagnostic-core.h"
+#include "tree-dfa.h"
 #include "stor-layout.h"
 #include "cfgrtl.h"
 #include "cfganal.h"
@@ -63,7 +65,7 @@
     return false;
 
   /* If the statement may throw an exception, it cannot be replaced.  */
-  if (stmt_could_throw_p (stmt))
+  if (stmt_could_throw_p (cfun, stmt))
     return false;
 
   /* Punt if there is more than 1 def.  */
@@ -888,6 +890,102 @@
     }
 }
 
+/* Create a default def for VAR.  */
+
+static void
+create_default_def (tree var, void *arg ATTRIBUTE_UNUSED)
+{
+  if (!is_gimple_reg (var))
+    return;
+
+  tree ssa = get_or_create_ssa_default_def (cfun, var);
+  gcc_assert (ssa);
+}
+
+/* Call CALLBACK for all PARM_DECLs and RESULT_DECLs for which
+   assign_parms may ask for a default partition.  */
+
+static void
+for_all_parms (void (*callback)(tree var, void *arg), void *arg)
+{
+  for (tree var = DECL_ARGUMENTS (current_function_decl); var;
+       var = DECL_CHAIN (var))
+    callback (var, arg);
+  if (!VOID_TYPE_P (TREE_TYPE (DECL_RESULT (current_function_decl))))
+    callback (DECL_RESULT (current_function_decl), arg);
+  if (cfun->static_chain_decl)
+    callback (cfun->static_chain_decl, arg);
+}
+
+/* We need to pass two arguments to set_parm_default_def_partition,
+   but for_all_parms only supports one.  Use a pair.  */
+
+typedef std::pair<var_map, bitmap> parm_default_def_partition_arg;
+
+/* Set in ARG's PARTS bitmap the bit corresponding to the partition in
+   ARG's MAP containing VAR's default def.  */
+
+static void
+set_parm_default_def_partition (tree var, void *arg_)
+{
+  parm_default_def_partition_arg *arg = (parm_default_def_partition_arg *)arg_;
+  var_map map = arg->first;
+  bitmap parts = arg->second;
+
+  if (!is_gimple_reg (var))
+    return;
+
+  tree ssa = ssa_default_def (cfun, var);
+  gcc_assert (ssa);
+
+  int version = var_to_partition (map, ssa);
+  gcc_assert (version != NO_PARTITION);
+
+  bool changed = bitmap_set_bit (parts, version);
+  gcc_assert (changed);
+}
+
+/* Allocate and return a bitmap that has a bit set for each partition
+   that contains a default def for a parameter.  */
+
+static bitmap
+get_parm_default_def_partitions (var_map map)
+{
+  bitmap parm_default_def_parts = BITMAP_ALLOC (NULL);
+
+  parm_default_def_partition_arg
+    arg = std::make_pair (map, parm_default_def_parts);
+
+  for_all_parms (set_parm_default_def_partition, &arg);
+
+  return parm_default_def_parts;
+}
+
+/* Allocate and return a bitmap that has a bit set for each partition
+   that contains an undefined value.  */
+
+static bitmap
+get_undefined_value_partitions (var_map map)
+{
+  bitmap undefined_value_parts = BITMAP_ALLOC (NULL);
+
+  for (unsigned int i = 1; i < num_ssa_names; i++)
+    {
+      tree var = ssa_name (i);
+      if (var
+	  && !virtual_operand_p (var)
+	  && !has_zero_uses (var)
+	  && ssa_undefined_value_p (var))
+	{
+	  const int p = var_to_partition (map, var);
+	  if (p != NO_PARTITION)
+	    bitmap_set_bit (undefined_value_parts, p);
+	}
+    }
+
+  return undefined_value_parts;
+}
+
 /* Given the out-of-ssa info object SA (with prepared partitions)
    eliminate all phi nodes in all basic blocks.  Afterwards no
    basic block will have phi nodes anymore and there are possibly
@@ -945,7 +1043,9 @@
   bitmap values = NULL;
   var_map map;
 
-  map = coalesce_ssa_name ();
+  for_all_parms (create_default_def, NULL);
+  map = init_var_map (num_ssa_names);
+  coalesce_ssa_name (map);
 
   /* Return to viewing the variable list as just all reference variables after
      coalescing has been performed.  */