| ------------------------------------------------------------------------------ |
| -- -- |
| -- 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) 2019-2021, 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; |
