The GNU Modula-2 front end to GCC

gm2-libs-pim/BitWordOps

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.