[thirdparty/gcc.git] / gcc / ada / libgnat / s-pack51.adb

------------------------------------------------------------------------------
--                                                                          --
--                         GNAT RUN-TIME COMPONENTS                         --
--                                                                          --
--                       S Y S T E M . P A C K _ 5 1                        --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2020, 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.      --
--                                                                          --
------------------------------------------------------------------------------

with System.Storage_Elements;
with System.Unsigned_Types;

package body System.Pack_51 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_51;
   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;

   ------------
   -- Get_51 --
   ------------

   function Get_51
     (Arr     : System.Address;
      N       : Natural;
      Rev_SSO : Boolean) return Bits_51
   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 => return RC.E0;
            when 1 => return RC.E1;
            when 2 => return RC.E2;
            when 3 => return RC.E3;
            when 4 => return RC.E4;
            when 5 => return RC.E5;
            when 6 => return RC.E6;
            when 7 => return RC.E7;
         end case;

      else
         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 if;
   end Get_51;

   ------------
   -- Set_51 --
   ------------

   procedure Set_51
     (Arr     : System.Address;
      N       : Natural;
      E       : Bits_51;
      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_51;

end System.Pack_51;
Commit	Line	Data
cacbc350 RK	1	------------------------------------------------------------------------------
cacbc350 RK	2	-- --
3084fecd	3	-- GNAT RUN-TIME COMPONENTS --
cacbc350 RK	4	-- --
	5	-- S Y S T E M . P A C K _ 5 1 --
	6	-- --
	7	-- B o d y --
	8	-- --
4b490c1e	9	-- Copyright (C) 1992-2020, Free Software Foundation, Inc. --
cacbc350 RK	10	-- --
	11	-- GNAT is free software; you can redistribute it and/or modify it under --
	12	-- terms of the GNU General Public License as published by the Free Soft- --
748086b7	13	-- ware Foundation; either version 3, or (at your option) any later ver- --
cacbc350 RK	14	-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
cacbc350 RK	15	-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
748086b7 JJ	16	-- or FITNESS FOR A PARTICULAR PURPOSE. --
	17	-- --
	18	-- As a special exception under Section 7 of GPL version 3, you are granted --
	19	-- additional permissions described in the GCC Runtime Library Exception, --
	20	-- version 3.1, as published by the Free Software Foundation. --
	21	-- --
	22	-- You should have received a copy of the GNU General Public License and --
	23	-- a copy of the GCC Runtime Library Exception along with this program; --
	24	-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
	25	-- <http://www.gnu.org/licenses/>. --
cacbc350 RK	26	-- --
cacbc350 RK	27	-- GNAT was originally developed by the GNAT team at New York University. --
71ff80dc	28	-- Extensive contributions were provided by Ada Core Technologies Inc. --
cacbc350 RK	29	-- --
	30	------------------------------------------------------------------------------
	31
	32	with System.Storage_Elements;
	33	with System.Unsigned_Types;
cacbc350 RK	34
	35	package body System.Pack_51 is
	36
7b536495 AC	37	subtype Bit_Order is System.Bit_Order;
	38	Reverse_Bit_Order : constant Bit_Order :=
	39	Bit_Order'Val (1 - Bit_Order'Pos (System.Default_Bit_Order));
	40
cacbc350 RK	41	subtype Ofs is System.Storage_Elements.Storage_Offset;
	42	subtype Uns is System.Unsigned_Types.Unsigned;
	43	subtype N07 is System.Unsigned_Types.Unsigned range 0 .. 7;
	44
	45	use type System.Storage_Elements.Storage_Offset;
	46	use type System.Unsigned_Types.Unsigned;
	47
	48	type Cluster is record
	49	E0, E1, E2, E3, E4, E5, E6, E7 : Bits_51;
	50	end record;
	51
	52	for Cluster use record
	53	E0 at 0 range 0 * Bits .. 0 * Bits + Bits - 1;
	54	E1 at 0 range 1 * Bits .. 1 * Bits + Bits - 1;
	55	E2 at 0 range 2 * Bits .. 2 * Bits + Bits - 1;
	56	E3 at 0 range 3 * Bits .. 3 * Bits + Bits - 1;
	57	E4 at 0 range 4 * Bits .. 4 * Bits + Bits - 1;
	58	E5 at 0 range 5 * Bits .. 5 * Bits + Bits - 1;
	59	E6 at 0 range 6 * Bits .. 6 * Bits + Bits - 1;
	60	E7 at 0 range 7 * Bits .. 7 * Bits + Bits - 1;
	61	end record;
	62
	63	for Cluster'Size use Bits * 8;
	64
	65	for Cluster'Alignment use Integer'Min (Standard'Maximum_Alignment,
	66	1 +
	67	1 * Boolean'Pos (Bits mod 2 = 0) +
	68	2 * Boolean'Pos (Bits mod 4 = 0));
	69	-- Use maximum possible alignment, given the bit field size, since this
	70	-- will result in the most efficient code possible for the field.
	71
	72	type Cluster_Ref is access Cluster;
	73
7b536495 AC	74	type Rev_Cluster is new Cluster
	75	with Bit_Order => Reverse_Bit_Order,
	76	Scalar_Storage_Order => Reverse_Bit_Order;
	77	type Rev_Cluster_Ref is access Rev_Cluster;
cacbc350 RK	78
	79	------------
	80	-- Get_51 --
	81	------------
	82
7b536495 AC	83	function Get_51
	84	(Arr : System.Address;
	85	N : Natural;
	86	Rev_SSO : Boolean) return Bits_51
	87	is
	88	A : constant System.Address := Arr + Bits * Ofs (Uns (N) / 8);
	89	C : Cluster_Ref with Address => A'Address, Import;
	90	RC : Rev_Cluster_Ref with Address => A'Address, Import;
cacbc350	91	begin
7b536495 AC	92	if Rev_SSO then
	93	case N07 (Uns (N) mod 8) is
	94	when 0 => return RC.E0;
	95	when 1 => return RC.E1;
	96	when 2 => return RC.E2;
	97	when 3 => return RC.E3;
	98	when 4 => return RC.E4;
	99	when 5 => return RC.E5;
	100	when 6 => return RC.E6;
	101	when 7 => return RC.E7;
	102	end case;
	103
	104	else
	105	case N07 (Uns (N) mod 8) is
	106	when 0 => return C.E0;
	107	when 1 => return C.E1;
	108	when 2 => return C.E2;
	109	when 3 => return C.E3;
	110	when 4 => return C.E4;
	111	when 5 => return C.E5;
	112	when 6 => return C.E6;
	113	when 7 => return C.E7;
	114	end case;
	115	end if;
cacbc350 RK	116	end Get_51;
	117
	118	------------
	119	-- Set_51 --
	120	------------
	121
7b536495 AC	122	procedure Set_51
	123	(Arr : System.Address;
	124	N : Natural;
	125	E : Bits_51;
	126	Rev_SSO : Boolean)
	127	is
	128	A : constant System.Address := Arr + Bits * Ofs (Uns (N) / 8);
	129	C : Cluster_Ref with Address => A'Address, Import;
	130	RC : Rev_Cluster_Ref with Address => A'Address, Import;
cacbc350	131	begin
7b536495 AC	132	if Rev_SSO then
	133	case N07 (Uns (N) mod 8) is
	134	when 0 => RC.E0 := E;
	135	when 1 => RC.E1 := E;
	136	when 2 => RC.E2 := E;
	137	when 3 => RC.E3 := E;
	138	when 4 => RC.E4 := E;
	139	when 5 => RC.E5 := E;
	140	when 6 => RC.E6 := E;
	141	when 7 => RC.E7 := E;
	142	end case;
	143	else
	144	case N07 (Uns (N) mod 8) is
	145	when 0 => C.E0 := E;
	146	when 1 => C.E1 := E;
	147	when 2 => C.E2 := E;
	148	when 3 => C.E3 := E;
	149	when 4 => C.E4 := E;
	150	when 5 => C.E5 := E;
	151	when 6 => C.E6 := E;
	152	when 7 => C.E7 := E;
	153	end case;
	154	end if;
cacbc350 RK	155	end Set_51;
	156
	157	end System.Pack_51;