------------------------------------------------------------------------------ -- -- -- 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) 2019-2022, 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.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;