+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNAT COMPILER COMPONENTS --
--- --
--- S Y S T E M . A R I T H _ 6 4 --
--- --
--- S p e c --
--- --
--- $Revision: 1.1.16.2 $
--- --
--- Copyright (C) 1994,1995,1996 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 unit provides software routines for doing arithmetic on 64-bit
--- signed integer values in cases where either overflow checking is
--- required, or intermediate results are longer than 64 bits.
-
-with Interfaces;
-
-package System.Arith_64 is
-pragma Pure (Arith_64);
-
- subtype Int64 is Interfaces.Integer_64;
-
- function Add_With_Ovflo_Check (X, Y : Int64) return Int64;
- -- Raises Constraint_Error if sum of operands overflows 64 bits,
- -- otherwise returns the 64-bit signed integer sum.
-
- function Subtract_With_Ovflo_Check (X, Y : Int64) return Int64;
- -- Raises Constraint_Error if difference of operands overflows 64
- -- bits, otherwise returns the 64-bit signed integer difference.
-
- function Multiply_With_Ovflo_Check (X, Y : Int64) return Int64;
- -- Raises Constraint_Error if product of operands overflows 64
- -- bits, otherwise returns the 64-bit signed integer difference.
-
- procedure Scaled_Divide
- (X, Y, Z : Int64;
- Q, R : out Int64;
- Round : Boolean);
- -- Performs the division of (X * Y) / Z, storing the quotient in Q
- -- and the remainder in R. Constraint_Error is raised if Z is zero,
- -- or if the quotient does not fit in 64-bits. Round indicates if
- -- the result should be rounded. If Round is False, then Q, R are
- -- the normal quotient and remainder from a truncating division.
- -- If Round is True, then Q is the rounded quotient. the remainder
- -- R is not affected by the setting of the Round flag.
-
- procedure Double_Divide
- (X, Y, Z : Int64;
- Q, R : out Int64;
- Round : Boolean);
- -- Performs the division X / (Y * Z), storing the quotient in Q and
- -- the remainder in R. Constraint_Error is raised if Y or Z is zero.
- -- Round indicates if the result should be rounded. If Round is False,
- -- then Q, R are the normal quotient and remainder from a truncating
- -- division. If Round is True, then Q is the rounded quotient. The
- -- remainder R is not affected by the setting of the Round flag. The
- -- result is known to be in range except for the noted possibility of
- -- Y or Z being zero, so no other overflow checks are required.
-
-end System.Arith_64;