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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- S Y S T E M . B I T F I E L D _ U T I L S --
-- --
-- S p e c --
-- --
-- Copyright (C) 2019-2023, 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.Bitfield_Utils;
package System.Bitfields is
-- Instances of the generic package in System.Bitfield_Utils. So far
-- we have just one, which defaults to the natural endianness of the
-- machine. We might someday want to support Scalar_Storage_Order.
-- Note: we use Long_Long_Integer'Size / 2 instead of 32 to support
-- specifying a target configuration file where the largest integer is
-- 32 bits instead of 64.
Val_Bits : constant := Long_Long_Integer'Size / 2;
Val_Bytes : constant := Val_Bits / System.Storage_Unit;
type Val_2 is mod 2**(Val_Bits * 2) with Alignment => Val_Bytes;
pragma Provide_Shift_Operators (Val_2);
type Val is mod 2**Val_Bits with Alignment => Val_Bytes;
-- Enabling checks on the instantiation of System.Bitfield_Utils.G makes a
-- latent visibility bug appear on strict alignment platforms related to
-- alignment checks. Work around it by suppressing these checks explicitly.
pragma Suppress (Alignment_Check);
package Utils is new System.Bitfield_Utils.G (Val, Val_2);
procedure Copy_Bitfield
(Src_Address : Address;
Src_Offset : Utils.Bit_Offset_In_Byte;
Dest_Address : Address;
Dest_Offset : Utils.Bit_Offset_In_Byte;
Size : Utils.Bit_Size)
renames Utils.Copy_Bitfield;
function Fast_Copy_Bitfield
(Src : Val_2;
Src_Offset : Utils.Bit_Offset;
Dest : Val_2;
Dest_Offset : Utils.Bit_Offset;
Size : Utils.Small_Size)
return Val_2 renames Utils.Fast_Copy_Bitfield;
end System.Bitfields;
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