2010-06-22 Paul Hilfinger <hilfinger@adacore.com>

	* a-nudira.adb, a-nudira.ads, a-nuflra.adb, a-nuflra.ads,
	gnat_rm.texi, impunit.adb, Makefile.rtl, s-rannum.adb
	(Random_Float_Template, Random): New method of creating
	uniform floating-point variables that allow the creation of all machine
	values in [0 .. 1).  

	* g-mbdira.adb, g-mbflra.adb, g-mbdira.ads, g-mbflra.ads: New file.

From-SVN: r161191

1 files changed, 9 insertions, 48 deletions

diff --git a/gcc/ada/a-nudira.ads b/gcc/ada/a-nudira.ads
index 425aa6f..03ce48b 100644
--- a/gcc/ada/a-nudira.ads
+++ b/gcc/ada/a-nudira.ads
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 S p e c                                  --
 --                                                                          --
---          Copyright (C) 1992-2009, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2010, 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 --
@@ -33,39 +33,24 @@
 --                                                                          --
 ------------------------------------------------------------------------------
 
---  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.
+--  Note: the implementation used in this package is a version of the
+--  Mersenne Twister. See s-rannum.adb for details and references.
 
-with Interfaces;
+with System.Random_Numbers;
 
 generic
    type Result_Subtype is (<>);
 
 package Ada.Numerics.Discrete_Random is
 
-   --  The algorithm used here is reliable from a required statistical point of
-   --  view only up to 48 bits. We try to behave reasonably in the case of
-   --  larger types, but we can't guarantee the required properties. So
-   --  generate a warning for these (slightly) dubious cases.
-
-   pragma Compile_Time_Warning
-     (Result_Subtype'Size > 48,
-      "statistical properties not guaranteed for size > 48");
-
    --  Basic facilities
 
    type Generator is limited private;
 
    function Random (Gen : Generator) return Result_Subtype;
 
-   procedure Reset (Gen : Generator);
    procedure Reset (Gen : Generator; Initiator : Integer);
+   procedure Reset (Gen : Generator);
 
    --  Advanced facilities
 
@@ -74,41 +59,17 @@ package Ada.Numerics.Discrete_Random is
    procedure Save  (Gen : Generator; To_State   : out State);
    procedure Reset (Gen : Generator; From_State : State);
 
-   Max_Image_Width : constant := 80;
+   Max_Image_Width : constant := System.Random_Numbers.Max_Image_Width;
 
    function Image (Of_State    : State)  return String;
    function Value (Coded_State : String) return State;
 
 private
-   subtype Int is Interfaces.Integer_32;
-   subtype Rst is Result_Subtype;
-
-   --  We prefer to use 14 digits for Flt, but some targets are more limited
-
-   type Flt is digits Positive'Min (14, Long_Long_Float'Digits);
-
-   RstF : constant Flt := Flt (Rst'Pos (Rst'First));
-   RstL : constant Flt := Flt (Rst'Pos (Rst'Last));
-
-   Offs : constant Flt := RstF - 0.5;
-
-   K1   : constant := 94_833_359;
-   K1F  : constant := 94_833_359.0;
-   K2   : constant := 47_416_679;
-   K2F  : constant := 47_416_679.0;
-   Scal : constant Flt := (RstL - RstF + 1.0) / (K1F * K2F);
-
-   type State is record
-      X1  : Int := Int (2999 ** 2);
-      X2  : Int := Int (1439 ** 2);
-      P   : Int := K1;
-      Q   : Int := K2;
-      FP  : Flt := K1F;
-      Scl : Flt := Scal;
-   end record;
 
    type Generator is limited record
-      Gen_State : State;
+      Rep : System.Random_Numbers.Generator;
    end record;
 
+   type State is new System.Random_Numbers.State;
+
 end Ada.Numerics.Discrete_Random;