--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/s-powtab.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,70 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+--                  S Y S T E M . P O W T E N _ T A B L E                   --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          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.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This package provides a powers of ten table used for real conversions
+
+package System.Powten_Table is
+   pragma Pure;
+
+   Maxpow : constant := 22;
+   --  The number of entries in this table is chosen to include powers of ten
+   --  that are exactly representable with long_long_float. Assuming that on
+   --  all targets we have 53 bits of mantissa for the type, the upper bound is
+   --  given by 53/(log 5). If the scaling factor for a string is greater than
+   --  Maxpow, it can be obtained by several multiplications, which is less
+   --  efficient than with a bigger table, but avoids anomalies at end points.
+
+   Powten : constant array (0 .. Maxpow) of Long_Long_Float :=
+      (00 => 1.0E+00,
+       01 => 1.0E+01,
+       02 => 1.0E+02,
+       03 => 1.0E+03,
+       04 => 1.0E+04,
+       05 => 1.0E+05,
+       06 => 1.0E+06,
+       07 => 1.0E+07,
+       08 => 1.0E+08,
+       09 => 1.0E+09,
+       10 => 1.0E+10,
+       11 => 1.0E+11,
+       12 => 1.0E+12,
+       13 => 1.0E+13,
+       14 => 1.0E+14,
+       15 => 1.0E+15,
+       16 => 1.0E+16,
+       17 => 1.0E+17,
+       18 => 1.0E+18,
+       19 => 1.0E+19,
+       20 => 1.0E+20,
+       21 => 1.0E+21,
+       22 => 1.0E+22);
+
+end System.Powten_Table;