| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- S Y S T E M . P A C K _ 4 0 -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2005, 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 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. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with System.Storage_Elements; |
| with System.Unsigned_Types; |
| with Unchecked_Conversion; |
| |
| package body System.Pack_40 is |
| |
| subtype Ofs is System.Storage_Elements.Storage_Offset; |
| subtype Uns is System.Unsigned_Types.Unsigned; |
| subtype N07 is System.Unsigned_Types.Unsigned range 0 .. 7; |
| |
| use type System.Storage_Elements.Storage_Offset; |
| use type System.Unsigned_Types.Unsigned; |
| |
| type Cluster is record |
| E0, E1, E2, E3, E4, E5, E6, E7 : Bits_40; |
| end record; |
| |
| for Cluster use record |
| E0 at 0 range 0 * Bits .. 0 * Bits + Bits - 1; |
| E1 at 0 range 1 * Bits .. 1 * Bits + Bits - 1; |
| E2 at 0 range 2 * Bits .. 2 * Bits + Bits - 1; |
| E3 at 0 range 3 * Bits .. 3 * Bits + Bits - 1; |
| E4 at 0 range 4 * Bits .. 4 * Bits + Bits - 1; |
| E5 at 0 range 5 * Bits .. 5 * Bits + Bits - 1; |
| E6 at 0 range 6 * Bits .. 6 * Bits + Bits - 1; |
| E7 at 0 range 7 * Bits .. 7 * Bits + Bits - 1; |
| end record; |
| |
| for Cluster'Size use Bits * 8; |
| |
| for Cluster'Alignment use Integer'Min (Standard'Maximum_Alignment, |
| 1 + |
| 1 * Boolean'Pos (Bits mod 2 = 0) + |
| 2 * Boolean'Pos (Bits mod 4 = 0)); |
| -- Use maximum possible alignment, given the bit field size, since this |
| -- will result in the most efficient code possible for the field. |
| |
| type Cluster_Ref is access Cluster; |
| |
| function To_Ref is new |
| Unchecked_Conversion (System.Address, Cluster_Ref); |
| |
| -- The following declarations are for the case where the address |
| -- passed to GetU_40 or SetU_40 is not guaranteed to be aligned. |
| -- These routines are used when the packed array is itself a |
| -- component of a packed record, and therefore may not be aligned. |
| |
| type ClusterU is new Cluster; |
| for ClusterU'Alignment use 1; |
| |
| type ClusterU_Ref is access ClusterU; |
| |
| function To_Ref is new |
| Unchecked_Conversion (System.Address, ClusterU_Ref); |
| |
| ------------ |
| -- Get_40 -- |
| ------------ |
| |
| function Get_40 (Arr : System.Address; N : Natural) return Bits_40 is |
| C : constant Cluster_Ref := To_Ref (Arr + Bits * Ofs (Uns (N) / 8)); |
| begin |
| case N07 (Uns (N) mod 8) is |
| when 0 => return C.E0; |
| when 1 => return C.E1; |
| when 2 => return C.E2; |
| when 3 => return C.E3; |
| when 4 => return C.E4; |
| when 5 => return C.E5; |
| when 6 => return C.E6; |
| when 7 => return C.E7; |
| end case; |
| end Get_40; |
| |
| ------------- |
| -- GetU_40 -- |
| ------------- |
| |
| function GetU_40 (Arr : System.Address; N : Natural) return Bits_40 is |
| C : constant ClusterU_Ref := To_Ref (Arr + Bits * Ofs (Uns (N) / 8)); |
| begin |
| case N07 (Uns (N) mod 8) is |
| when 0 => return C.E0; |
| when 1 => return C.E1; |
| when 2 => return C.E2; |
| when 3 => return C.E3; |
| when 4 => return C.E4; |
| when 5 => return C.E5; |
| when 6 => return C.E6; |
| when 7 => return C.E7; |
| end case; |
| end GetU_40; |
| |
| ------------ |
| -- Set_40 -- |
| ------------ |
| |
| procedure Set_40 (Arr : System.Address; N : Natural; E : Bits_40) is |
| C : constant Cluster_Ref := To_Ref (Arr + Bits * Ofs (Uns (N) / 8)); |
| begin |
| case N07 (Uns (N) mod 8) is |
| when 0 => C.E0 := E; |
| when 1 => C.E1 := E; |
| when 2 => C.E2 := E; |
| when 3 => C.E3 := E; |
| when 4 => C.E4 := E; |
| when 5 => C.E5 := E; |
| when 6 => C.E6 := E; |
| when 7 => C.E7 := E; |
| end case; |
| end Set_40; |
| |
| ------------- |
| -- SetU_40 -- |
| ------------- |
| |
| procedure SetU_40 (Arr : System.Address; N : Natural; E : Bits_40) is |
| C : constant ClusterU_Ref := To_Ref (Arr + Bits * Ofs (Uns (N) / 8)); |
| begin |
| case N07 (Uns (N) mod 8) is |
| when 0 => C.E0 := E; |
| when 1 => C.E1 := E; |
| when 2 => C.E2 := E; |
| when 3 => C.E3 := E; |
| when 4 => C.E4 := E; |
| when 5 => C.E5 := E; |
| when 6 => C.E6 := E; |
| when 7 => C.E7 := E; |
| end case; |
| end SetU_40; |
| |
| end System.Pack_40; |
