--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/s-valdec.adb	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,68 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+--                       S Y S T E M . V A L _ D E C                        --
+--                                                                          --
+--                                 B o d y                                  --
+--                                                                          --
+--          Copyright (C) 1992-2017, Free Software Foundation, Inc.         --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+with System.Val_Real; use System.Val_Real;
+
+package body System.Val_Dec is
+
+   ------------------
+   -- Scan_Decimal --
+   ------------------
+
+   --  For decimal types where Size < Integer'Size, it is fine to use
+   --  the floating-point circuit, since it certainly has sufficient
+   --  precision for any reasonable hardware, and we just don't support
+   --  things on junk hardware.
+
+   function Scan_Decimal
+     (Str   : String;
+      Ptr   : not null access Integer;
+      Max   : Integer;
+      Scale : Integer) return Integer
+   is
+      Val : Long_Long_Float;
+   begin
+      Val := Scan_Real (Str, Ptr, Max);
+      return Integer (Val * 10.0 ** Scale);
+   end Scan_Decimal;
+
+   -------------------
+   -- Value_Decimal --
+   -------------------
+
+   --  Again, we use the real circuit for this purpose
+
+   function Value_Decimal (Str : String; Scale : Integer) return Integer is
+   begin
+      return Integer (Value_Real (Str) * 10.0 ** Scale);
+   end Value_Decimal;
+
+end System.Val_Dec;