1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- 4-- -- 5-- 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 -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 2002-2020, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This package contains functions for runtime operations on boolean vectors 33 34package System.Vectors.Boolean_Operations is 35 pragma Pure; 36 37 -- Although in general the boolean operations on arrays of booleans are 38 -- identical to operations on arrays of unsigned words of the same size, 39 -- for the "not" operator this is not the case as False is typically 40 -- represented by 0 and true by 1. 41 42 function "not" (Item : Vectors.Vector) return Vectors.Vector; 43 44 -- The three boolean operations "nand", "nor" and "nxor" are needed 45 -- for cases where the compiler moves boolean array operations into 46 -- the body of the loop that iterates over the array elements. 47 48 -- Note the following equivalences: 49 -- (not X) or (not Y) = not (X and Y) = Nand (X, Y) 50 -- (not X) and (not Y) = not (X or Y) = Nor (X, Y) 51 -- (not X) xor (not Y) = X xor Y 52 -- X xor (not Y) = not (X xor Y) = Nxor (X, Y) 53 54 function Nand (Left, Right : Boolean) return Boolean; 55 function Nor (Left, Right : Boolean) return Boolean; 56 function Nxor (Left, Right : Boolean) return Boolean; 57 58 function Nand (Left, Right : Vectors.Vector) return Vectors.Vector; 59 function Nor (Left, Right : Vectors.Vector) return Vectors.Vector; 60 function Nxor (Left, Right : Vectors.Vector) return Vectors.Vector; 61 62 pragma Inline_Always ("not"); 63 pragma Inline_Always (Nand); 64 pragma Inline_Always (Nor); 65 pragma Inline_Always (Nxor); 66end System.Vectors.Boolean_Operations; 67