⟦f127159e3⟧

E3 Source Code



generic
    type Integer_Type is range <>;
package Generic_Bit_Operations is

    -- Operations on an integer type as an array of bits.
    -- Bit numbering is left to right, starting from 0.
    -- Arguments specified outside bit range raise Constraint_Error

    -- Note :- The CDFs may allocate 32 bits for integer subtypes.
    -- For eg: integer  range -128..127  may   result in  the
    -- allocation of a 32 bit integer. Hence integer_type'size
    -- must not be relied upon when using this pacakge .
    -- However this package will compute the offset of Bit 0
    -- for any type properly.

    -- 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_Type; Start : Natural; Length : Natural)
                     return Integer_Type;

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

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

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

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

end Generic_Bit_Operations;
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⟦f127159e3⟧ Ada Source

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E3 Source Code

E3 Meta Data
