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Diffstat (limited to 'gcc/ada/a-nuflra.ads')
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diff --git a/gcc/ada/a-nuflra.ads b/gcc/ada/a-nuflra.ads new file mode 100644 index 00000000000..79f9da5f640 --- /dev/null +++ b/gcc/ada/a-nuflra.ads @@ -0,0 +1,101 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME COMPONENTS -- +-- -- +-- A D A . N U M E R I C S . F L O A T _ R A N D O M -- +-- -- +-- S p e c -- +-- -- +-- $Revision: 1.12 $ -- +-- -- +-- Copyright (C) 1992-1998 Free Software Foundation, Inc. -- +-- -- +-- This specification is derived from the Ada Reference Manual for use with -- +-- GNAT. The copyright notice above, and the license provisions that follow -- +-- apply solely to the contents of the part following the private keyword. -- +-- -- +-- 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. -- +-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +-- Note: the implementation used in this package was contributed by +-- Robert Eachus. It is based on the work of L. Blum, M. Blum, and +-- M. Shub, SIAM Journal of Computing, Vol 15. No 2, May 1986. The +-- particular choices for P and Q chosen here guarantee a period of +-- 562,085,314,430,582 (about 2**49), and the generated sequence has +-- excellent randomness properties. For further details, see the +-- paper "Fast Generation of Trustworthy Random Numbers", by Robert +-- Eachus, which describes both the algorithm and the efficient +-- implementation approach used here. This paper is available at +-- the Ada Core Technologies web site (http://www.gnat.com). + +with Interfaces; + +package Ada.Numerics.Float_Random is + + -- Basic facilities + + type Generator is limited private; + + subtype Uniformly_Distributed is Float range 0.0 .. 1.0; + + function Random (Gen : Generator) return Uniformly_Distributed; + + procedure Reset (Gen : Generator); + procedure Reset (Gen : Generator; Initiator : Integer); + + -- Advanced facilities + + type State is private; + + procedure Save (Gen : Generator; To_State : out State); + procedure Reset (Gen : Generator; From_State : State); + + Max_Image_Width : constant := 80; + + function Image (Of_State : State) return String; + function Value (Coded_State : String) return State; + +private + type Int is new Interfaces.Integer_32; + type Flt is digits 14; + + K1 : constant := 94_833_359; + K1F : constant := 94_833_359.0; + K2 : constant := 47_416_679; + K2F : constant := 47_416_679.0; + Scal : constant := 1.0 / (K1F * K2F); + + type State is record + X1 : Int := 2999 ** 2; -- Square mod p + X2 : Int := 1439 ** 2; -- Square mod q + P : Int := K1; + Q : Int := K2; + X : Int := 1; + Scl : Flt := Scal; + end record; + + type Generator is limited record + Gen_State : State; + end record; + +end Ada.Numerics.Float_Random; |