------------------------------------------------------------------------------ -- -- -- GNU ADA RUNTIME 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 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, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, 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;