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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . A D D R E S S _ O P E R A T I O N S --
-- --
-- S p e c --
-- --
-- Copyright (C) 2004-2009, 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 3, 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. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package provides arithmetic and logical operations on type Address.
-- It is intended for use by other packages in the System hierarchy. For
-- applications requiring this capability, see System.Storage_Elements or
-- the operations introduced in System.Aux_DEC;
-- The reason we need this package is that arithmetic operations may not
-- be available in the case where type Address is non-private and the
-- operations have been made abstract in the spec of System (to avoid
-- inappropriate use by applications programs). In addition, the logical
-- operations may not be available if type Address is a signed integer.
pragma Compiler_Unit;
package System.Address_Operations is
pragma Pure;
-- The semantics of the arithmetic operations are those that apply to
-- a modular type with the same length as Address, i.e. they provide
-- twos complement wrap around arithmetic treating the address value
-- as an unsigned value, with no overflow checking.
-- Note that we do not use the infix names for these operations to
-- avoid problems with ambiguities coming from declarations in package
-- Standard (which may or may not be visible depending on the exact
-- form of the declaration of type System.Address).
-- For addition, subtraction, and multiplication, the effect of overflow
-- is 2's complement wrapping (as though the type Address were unsigned).
-- For division and modulus operations, the caller is responsible for
-- ensuring that the Right argument is non-zero, and the effect of the
-- call is not specified if a zero argument is passed.
function AddA (Left, Right : Address) return Address;
function SubA (Left, Right : Address) return Address;
function MulA (Left, Right : Address) return Address;
function DivA (Left, Right : Address) return Address;
function ModA (Left, Right : Address) return Address;
-- The semantics of the logical operations are those that apply to
-- a modular type with the same length as Address, i.e. they provide
-- bit-wise operations on all bits of the value (including the sign
-- bit if Address is a signed integer type).
function AndA (Left, Right : Address) return Address;
function OrA (Left, Right : Address) return Address;
pragma Inline_Always (AddA);
pragma Inline_Always (SubA);
pragma Inline_Always (MulA);
pragma Inline_Always (DivA);
pragma Inline_Always (ModA);
pragma Inline_Always (AndA);
pragma Inline_Always (OrA);
end System.Address_Operations;
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