⟦f76ba2db2⟧

E3 Source Code



package Bit_Operations is

    -- Operations on Integer and Long_Integer as an array of bits.
    -- Bit numbering is left to right, 0..31 and 0..63.
    -- Arguments specified outside bit range raise Constraint_Error


    -- Extract the bits from Start .. Start + Length - 1.  Equivalent to
    -- Logical_And with 1 in bits of the extraction range and 0 elsewhere.
    function Extract
                (W : Integer; Start : Natural; Length : Natural) return Integer;
    function Extract (W : Long_Integer; Start : Natural; Length : Natural)
                     return Long_Integer;

    -- Extract the single bit at B and return as Boolean
    -- Equivalent to Extract (W, B, 1) /= 0
    function Test_Bit (W : Integer; B : Natural)      return Boolean;
    function Test_Bit (W : Long_Integer; B : Natural) return Boolean;

    -- Replace the specified bits of Into with the rightmost Length bits of W.
    function Insert (W, Into : Integer; Start : Natural; Length : Natural)
                    return Integer;
    function Insert (W, Into : Long_Integer; Start : Natural; Length : Natural)
                    return Long_Integer;

    -- Set the specified Bit to One or Zero
    procedure Set_Bit_To_One  (W : in out Integer; B : Natural);
    procedure Set_Bit_To_One  (W : in out Long_Integer; B : Natural);
    procedure Set_Bit_To_Zero (W : in out Integer; B : Natural);
    procedure Set_Bit_To_Zero (W : in out Long_Integer; B : Natural);

    -- Logical operations on two operands.
    -- For shift operations, positive arguments shift Left and negative
    -- arguments shift Right.
    -- Intermediate results are stored as Long_Integer, so shifting
    -- ones into positions outside of Integer will raise Numeric_Error.
    function Logical_And   (X, Y : Integer)                return Integer;
    function Logical_And   (X, Y : Long_Integer)           return Long_Integer;
    function Logical_Or    (X, Y : Integer)                return Integer;
    function Logical_Or    (X, Y : Long_Integer)           return Long_Integer;
    function Logical_Xor   (X, Y : Integer)                return Integer;
    function Logical_Xor   (X, Y : Long_Integer)           return Long_Integer;
    function Logical_Not   (X : Integer)                   return Integer;
    function Logical_Not   (X : Long_Integer)              return Long_Integer;
    function Logical_Shift (X : Integer; Amount : Integer) return Integer;
    function Logical_Shift
                (X : Long_Integer; Amount : Integer)       return Long_Integer;

    pragma Module_Name (4, 828);
    pragma Subsystem (Miscellaneous);

end Bit_Operations;
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⟦f76ba2db2⟧ Ada Source

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