(* BitWordOps.def provides a Logitech-3.0 compatible library.

Copyright (C) 2007-2024 Free Software Foundation, Inc.
Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.

This file is part of GNU Modula-2.

GNU Modula-2 is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.

GNU Modula-2 is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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/>.  *)

DEFINITION MODULE BitWordOps ;

FROM SYSTEM IMPORT WORD ;


(*
   GetBits - returns the bits firstBit..lastBit from source.
             Bit 0 of word maps onto the firstBit of source.
*)

PROCEDURE GetBits (source: WORD; firstBit, lastBit: CARDINAL) : WORD ;


(*
   SetBits - sets bits in, word, starting at, firstBit, and ending at,
             lastBit, with, pattern.  The bit zero of, pattern, will
             be placed into, word, at position, firstBit.
*)

PROCEDURE SetBits (VAR word: WORD; firstBit, lastBit: CARDINAL;
                   pattern: WORD) ;


(*
   WordAnd - returns a bitwise (left AND right)
*)

PROCEDURE WordAnd (left, right: WORD) : WORD ;


(*
   WordOr - returns a bitwise (left OR right)
*)

PROCEDURE WordOr (left, right: WORD) : WORD ;


(*
   WordXor - returns a bitwise (left XOR right)
*)

PROCEDURE WordXor (left, right: WORD) : WORD ;


(*
   WordNot - returns a word with all bits inverted.
*)

PROCEDURE WordNot (word: WORD) : WORD ;


(*
   WordShr - returns a, word, which has been shifted, count
             bits to the right.
*)

PROCEDURE WordShr (word: WORD; count: CARDINAL) : WORD ;


(*
   WordShl - returns a, word, which has been shifted, count
             bits to the left.
*)

PROCEDURE WordShl (word: WORD; count: CARDINAL) : WORD ;


(*
   WordSar - shift word arthemetic right.  Preserves the top
             end bit and as the value is shifted right.
*)

PROCEDURE WordSar (word: WORD; count: CARDINAL) : WORD ;


(*
   WordRor - returns a, word, which has been rotated, count
             bits to the right.
*)

PROCEDURE WordRor (word: WORD; count: CARDINAL) : WORD ;


(*
   WordRol - returns a, word, which has been rotated, count
             bits to the left.
*)

PROCEDURE WordRol (word: WORD; count: CARDINAL) : WORD ;


(*
   HighByte - returns the top byte only from, word.
              The byte is returned in the bottom byte
              in the return value.
*)

PROCEDURE HighByte (word: WORD) : WORD ;


(*
   LowByte - returns the low byte only from, word.
             The byte is returned in the bottom byte
             in the return value.
*)

PROCEDURE LowByte (word: WORD) : WORD ;


(*
   Swap - byte flips the contents of word.
*)

PROCEDURE Swap (word: WORD) : WORD ;


END BitWordOps.
