------------------------------------------------------------------------------ -- -- -- GNAT RUN-TIME COMPONENTS -- -- -- -- S Y S T E M . P A C K _ 2 0 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2024, 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 -- -- . -- -- -- -- 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; package body System.Pack_20 is subtype Bit_Order is System.Bit_Order; Reverse_Bit_Order : constant Bit_Order := Bit_Order'Val (1 - Bit_Order'Pos (System.Default_Bit_Order)); 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_20; 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; type Rev_Cluster is new Cluster with Bit_Order => Reverse_Bit_Order, Scalar_Storage_Order => Reverse_Bit_Order; type Rev_Cluster_Ref is access Rev_Cluster; -- The following declarations are for the case where the address -- passed to GetU_20 or SetU_20 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; type Rev_ClusterU is new ClusterU with Bit_Order => Reverse_Bit_Order, Scalar_Storage_Order => Reverse_Bit_Order; type Rev_ClusterU_Ref is access Rev_ClusterU; ------------ -- Get_20 -- ------------ function Get_20 (Arr : System.Address; N : Natural; Rev_SSO : Boolean) return Bits_20 is A : constant System.Address := Arr + Bits * Ofs (Uns (N) / 8); C : Cluster_Ref with Address => A'Address, Import; RC : Rev_Cluster_Ref with Address => A'Address, Import; begin return (if Rev_SSO then (case N07 (Uns (N) mod 8) is when 0 => RC.E0, when 1 => RC.E1, when 2 => RC.E2, when 3 => RC.E3, when 4 => RC.E4, when 5 => RC.E5, when 6 => RC.E6, when 7 => RC.E7) else (case N07 (Uns (N) mod 8) is when 0 => C.E0, when 1 => C.E1, when 2 => C.E2, when 3 => C.E3, when 4 => C.E4, when 5 => C.E5, when 6 => C.E6, when 7 => C.E7) ); end Get_20; ------------- -- GetU_20 -- ------------- function GetU_20 (Arr : System.Address; N : Natural; Rev_SSO : Boolean) return Bits_20 is A : constant System.Address := Arr + Bits * Ofs (Uns (N) / 8); C : ClusterU_Ref with Address => A'Address, Import; RC : Rev_ClusterU_Ref with Address => A'Address, Import; begin return (if Rev_SSO then (case N07 (Uns (N) mod 8) is when 0 => RC.E0, when 1 => RC.E1, when 2 => RC.E2, when 3 => RC.E3, when 4 => RC.E4, when 5 => RC.E5, when 6 => RC.E6, when 7 => RC.E7) else (case N07 (Uns (N) mod 8) is when 0 => C.E0, when 1 => C.E1, when 2 => C.E2, when 3 => C.E3, when 4 => C.E4, when 5 => C.E5, when 6 => C.E6, when 7 => C.E7) ); end GetU_20; ------------ -- Set_20 -- ------------ procedure Set_20 (Arr : System.Address; N : Natural; E : Bits_20; Rev_SSO : Boolean) is A : constant System.Address := Arr + Bits * Ofs (Uns (N) / 8); C : Cluster_Ref with Address => A'Address, Import; RC : Rev_Cluster_Ref with Address => A'Address, Import; begin if Rev_SSO then case N07 (Uns (N) mod 8) is when 0 => RC.E0 := E; when 1 => RC.E1 := E; when 2 => RC.E2 := E; when 3 => RC.E3 := E; when 4 => RC.E4 := E; when 5 => RC.E5 := E; when 6 => RC.E6 := E; when 7 => RC.E7 := E; end case; else 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 if; end Set_20; ------------- -- SetU_20 -- ------------- procedure SetU_20 (Arr : System.Address; N : Natural; E : Bits_20; Rev_SSO : Boolean) is A : constant System.Address := Arr + Bits * Ofs (Uns (N) / 8); C : ClusterU_Ref with Address => A'Address, Import; RC : Rev_ClusterU_Ref with Address => A'Address, Import; begin if Rev_SSO then case N07 (Uns (N) mod 8) is when 0 => RC.E0 := E; when 1 => RC.E1 := E; when 2 => RC.E2 := E; when 3 => RC.E3 := E; when 4 => RC.E4 := E; when 5 => RC.E5 := E; when 6 => RC.E6 := E; when 7 => RC.E7 := E; end case; else 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 if; end SetU_20; end System.Pack_20;