1 files changed, 53 insertions, 0 deletions
diff --git a/gcc/ada/s-strhas.adb b/gcc/ada/s-strhas.adb
new file mode 100644
index 00000000000..2e3a730d27b
--- /dev/null
+++ b/gcc/ada/s-strhas.adb
@@ -0,0 +1,53 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+--                    S Y S T E M . S T R I N G _ H A S H                   --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--             Copyright (C) 2009, 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.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+package body System.String_Hash is
+
+   --  Compute a hash value for a key. The approach here is follows
+   --  the algorithm used in GNU Awk and the ndbm substitute SDBM by
+   --  Ozan Yigit.
+
+   function Hash (Key : Key_Type) return Hash_Type
+   is
+      function Shift_Left
+        (Value : Hash_Type; Amount : Natural) return Hash_Type;
+      pragma Import (Intrinsic, Shift_Left);
+
+      H : Hash_Type := 0;
+   begin
+      for J in Key'Range loop
+         H := Char_Type'Pos (Key (J))
+           + Shift_Left (H, 6) + Shift_Left (H, 16) - H;
+      end loop;
+      return H;
+   end Hash;
+
+end System.String_Hash;