67 lines
3.8 KiB
Ada
67 lines
3.8 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
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-- --
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-- 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 --
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-- --
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-- S p e c --
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-- --
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-- Copyright (C) 2002-2009, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. --
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-- --
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-- As a special exception under Section 7 of GPL version 3, you are granted --
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-- additional permissions described in the GCC Runtime Library Exception, --
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-- version 3.1, as published by the Free Software Foundation. --
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-- --
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-- You should have received a copy of the GNU General Public License and --
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-- a copy of the GCC Runtime Library Exception along with this program; --
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-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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-- <http://www.gnu.org/licenses/>. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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-- This package contains functions for runtime operations on boolean vectors
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package System.Vectors.Boolean_Operations is
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pragma Pure;
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-- Although in general the boolean operations on arrays of booleans are
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-- identical to operations on arrays of unsigned words of the same size,
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-- for the "not" operator this is not the case as False is typically
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-- represented by 0 and true by 1.
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function "not" (Item : Vectors.Vector) return Vectors.Vector;
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-- The three boolean operations "nand", "nor" and "nxor" are needed
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-- for cases where the compiler moves boolean array operations into
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-- the body of the loop that iterates over the array elements.
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-- Note the following equivalences:
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-- (not X) or (not Y) = not (X and Y) = Nand (X, Y)
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-- (not X) and (not Y) = not (X or Y) = Nor (X, Y)
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-- (not X) xor (not Y) = X xor Y
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-- X xor (not Y) = not (X xor Y) = Nxor (X, Y)
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function Nand (Left, Right : Boolean) return Boolean;
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function Nor (Left, Right : Boolean) return Boolean;
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function Nxor (Left, Right : Boolean) return Boolean;
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function Nand (Left, Right : Vectors.Vector) return Vectors.Vector;
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function Nor (Left, Right : Vectors.Vector) return Vectors.Vector;
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function Nxor (Left, Right : Vectors.Vector) return Vectors.Vector;
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pragma Inline_Always ("not");
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pragma Inline_Always (Nand);
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pragma Inline_Always (Nor);
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pragma Inline_Always (Nxor);
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end System.Vectors.Boolean_Operations;
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