------------------------------------------------------------------------------ -- -- -- 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 -- -- . -- -- -- -- 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;