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Diffstat (limited to 'gcc/ada/a-szbzha.adb')
| -rw-r--r-- | gcc/ada/a-szbzha.adb | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/gcc/ada/a-szbzha.adb b/gcc/ada/a-szbzha.adb new file mode 100644 index 00000000000..458f47757d4 --- /dev/null +++ b/gcc/ada/a-szbzha.adb @@ -0,0 +1,60 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT LIBRARY COMPONENTS -- +-- -- +-- A D A . S T R I N G S . W I D E _ W I D E _ B O U N D E D . -- +-- W I D E _ W I D E _ H A S H -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 2004-2006 Free Software Foundation, Inc. -- +-- -- +-- This specification is derived from the Ada Reference Manual for use with -- +-- GNAT. The copyright notice above, and the license provisions that follow -- +-- apply solely to the contents of the part following the private keyword. -- +-- -- +-- 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 2, 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. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING. If not, write -- +-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- +-- Boston, MA 02110-1301, USA. -- +-- -- +-- As a special exception, if other files instantiate generics from this -- +-- unit, or you link this unit with other files to produce an executable, -- +-- this unit does not by itself cause the resulting executable to be -- +-- covered by the GNU General Public License. This exception does not -- +-- however invalidate any other reasons why the executable file might be -- +-- covered by the GNU Public License. -- +-- -- +-- This unit was originally developed by Matthew J Heaney. -- +------------------------------------------------------------------------------ + +-- Note: source of this algorithm: GNAT.HTable.Hash (g-htable.adb) + +function Ada.Strings.Wide_Wide_Bounded.Wide_Wide_Hash + (Key : Bounded.Bounded_Wide_Wide_String) + return Containers.Hash_Type +is + use Ada.Containers; + + function Rotate_Left + (Value : Hash_Type; + Amount : Natural) return Hash_Type; + pragma Import (Intrinsic, Rotate_Left); + + Tmp : Hash_Type; + +begin + Tmp := 0; + for J in 1 .. Bounded.Length (Key) loop + Tmp := Rotate_Left (Tmp, 3) + + Wide_Wide_Character'Pos (Bounded.Element (Key, J)); + end loop; + + return Tmp; +end Ada.Strings.Wide_Wide_Bounded.Wide_Wide_Hash; |