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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- S Y S T E M . V E C T O R S . B O O L E A N _ O P E R A T I O N S --
-- --
-- S p e c --
-- --
-- Copyright (C) 2002-2005 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 2, 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. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
-- Boston, MA 02110-1301, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package contains functions for runtime operations on boolean vectors
package System.Vectors.Boolean_Operations is
pragma Pure (Boolean_Operations);
-- Although in general the boolean operations on arrays of booleans are
-- identical to operations on arrays of unsigned words of the same size,
-- for the "not" operator this is not the case as False is typically
-- represented by 0 and true by 1.
function "not" (Item : Vectors.Vector) return Vectors.Vector;
-- The three boolean operations "nand", "nor" and "nxor" are needed
-- for cases where the compiler moves boolean array operations into
-- the body of the loop that iterates over the array elements.
-- Note the following equivalences:
-- (not X) or (not Y) = not (X and Y) = Nand (X, Y)
-- (not X) and (not Y) = not (X or Y) = Nor (X, Y)
-- (not X) xor (not Y) = X xor Y
-- X xor (not Y) = not (X xor Y) = Nxor (X, Y)
function Nand (Left, Right : Boolean) return Boolean;
function Nor (Left, Right : Boolean) return Boolean;
function Nxor (Left, Right : Boolean) return Boolean;
function Nand (Left, Right : Vectors.Vector) return Vectors.Vector;
function Nor (Left, Right : Vectors.Vector) return Vectors.Vector;
function Nxor (Left, Right : Vectors.Vector) return Vectors.Vector;
pragma Inline_Always ("not");
pragma Inline_Always (Nand);
pragma Inline_Always (Nor);
pragma Inline_Always (Nxor);
end System.Vectors.Boolean_Operations;
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