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Diffstat (limited to 'gcc-4.9/gcc/ada/g-rannum.adb')
| -rw-r--r-- | gcc-4.9/gcc/ada/g-rannum.adb | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/ada/g-rannum.adb b/gcc-4.9/gcc/ada/g-rannum.adb new file mode 100644 index 000000000..a868f0812 --- /dev/null +++ b/gcc-4.9/gcc/ada/g-rannum.adb @@ -0,0 +1,343 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME COMPONENTS -- +-- -- +-- G N A T . R A N D O M _ N U M B E R S -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 2007-2013, 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. -- +-- -- +------------------------------------------------------------------------------ + +with Ada.Numerics.Long_Elementary_Functions; +use Ada.Numerics.Long_Elementary_Functions; +with Ada.Unchecked_Conversion; + +with System.Random_Numbers; use System.Random_Numbers; + +package body GNAT.Random_Numbers is + + Sys_Max_Image_Width : constant := System.Random_Numbers.Max_Image_Width; + + subtype Image_String is String (1 .. Max_Image_Width); + + -- Utility function declarations + + procedure Insert_Image + (S : in out Image_String; + Index : Integer; + V : Integer_64); + -- Insert string representation of V in S starting at position Index + + --------------- + -- To_Signed -- + --------------- + + function To_Signed is + new Ada.Unchecked_Conversion (Unsigned_32, Integer_32); + function To_Signed is + new Ada.Unchecked_Conversion (Unsigned_64, Integer_64); + + ------------------ + -- Insert_Image -- + ------------------ + + procedure Insert_Image + (S : in out Image_String; + Index : Integer; + V : Integer_64) + is + Image : constant String := Integer_64'Image (V); + begin + S (Index .. Index + Image'Length - 1) := Image; + end Insert_Image; + + --------------------- + -- Random_Discrete -- + --------------------- + + function Random_Discrete + (Gen : Generator; + Min : Result_Subtype := Default_Min; + Max : Result_Subtype := Result_Subtype'Last) return Result_Subtype + is + function F is + new System.Random_Numbers.Random_Discrete + (Result_Subtype, Default_Min); + begin + return F (Gen.Rep, Min, Max); + end Random_Discrete; + + -------------------------- + -- Random_Decimal_Fixed -- + -------------------------- + + function Random_Decimal_Fixed + (Gen : Generator; + Min : Result_Subtype := Default_Min; + Max : Result_Subtype := Result_Subtype'Last) return Result_Subtype + is + subtype IntV is Integer_64 range + Integer_64'Integer_Value (Min) .. + Integer_64'Integer_Value (Max); + function R is new Random_Discrete (Integer_64, IntV'First); + begin + return Result_Subtype'Fixed_Value (R (Gen, IntV'First, IntV'Last)); + end Random_Decimal_Fixed; + + --------------------------- + -- Random_Ordinary_Fixed -- + --------------------------- + + function Random_Ordinary_Fixed + (Gen : Generator; + Min : Result_Subtype := Default_Min; + Max : Result_Subtype := Result_Subtype'Last) return Result_Subtype + is + subtype IntV is Integer_64 range + Integer_64'Integer_Value (Min) .. + Integer_64'Integer_Value (Max); + function R is new Random_Discrete (Integer_64, IntV'First); + begin + return Result_Subtype'Fixed_Value (R (Gen, IntV'First, IntV'Last)); + end Random_Ordinary_Fixed; + + ------------ + -- Random -- + ------------ + + function Random (Gen : Generator) return Float is + begin + return Random (Gen.Rep); + end Random; + + function Random (Gen : Generator) return Long_Float is + begin + return Random (Gen.Rep); + end Random; + + function Random (Gen : Generator) return Interfaces.Unsigned_32 is + begin + return Random (Gen.Rep); + end Random; + + function Random (Gen : Generator) return Interfaces.Unsigned_64 is + begin + return Random (Gen.Rep); + end Random; + + function Random (Gen : Generator) return Integer_64 is + begin + return To_Signed (Unsigned_64'(Random (Gen))); + end Random; + + function Random (Gen : Generator) return Integer_32 is + begin + return To_Signed (Unsigned_32'(Random (Gen))); + end Random; + + function Random (Gen : Generator) return Long_Integer is + function Random_Long_Integer is new Random_Discrete (Long_Integer); + begin + return Random_Long_Integer (Gen); + end Random; + + function Random (Gen : Generator) return Integer is + function Random_Integer is new Random_Discrete (Integer); + begin + return Random_Integer (Gen); + end Random; + + ------------------ + -- Random_Float -- + ------------------ + + function Random_Float (Gen : Generator) return Result_Subtype is + function F is new System.Random_Numbers.Random_Float (Result_Subtype); + begin + return F (Gen.Rep); + end Random_Float; + + --------------------- + -- Random_Gaussian -- + --------------------- + + -- Generates pairs of normally distributed values using the polar method of + -- G. E. P. Box, M. E. Muller, and G. Marsaglia. See Donald E. Knuth, The + -- Art of Computer Programming, Vol 2: Seminumerical Algorithms, section + -- 3.4.1, subsection C, algorithm P. Returns half of the pair on each call, + -- using the Next_Gaussian field of Gen to hold the second member on + -- even-numbered calls. + + function Random_Gaussian (Gen : Generator) return Long_Float is + G : Generator renames Gen'Unrestricted_Access.all; + + V1, V2, Rad2, Mult : Long_Float; + + begin + if G.Have_Gaussian then + G.Have_Gaussian := False; + return G.Next_Gaussian; + + else + loop + V1 := 2.0 * Random (G) - 1.0; + V2 := 2.0 * Random (G) - 1.0; + Rad2 := V1 ** 2 + V2 ** 2; + exit when Rad2 < 1.0 and then Rad2 /= 0.0; + end loop; + + -- Now V1 and V2 are coordinates in the unit circle + + Mult := Sqrt (-2.0 * Log (Rad2) / Rad2); + G.Next_Gaussian := V2 * Mult; + G.Have_Gaussian := True; + return Long_Float'Machine (V1 * Mult); + end if; + end Random_Gaussian; + + function Random_Gaussian (Gen : Generator) return Float is + V : constant Long_Float := Random_Gaussian (Gen); + begin + return Float'Machine (Float (V)); + end Random_Gaussian; + + ----------- + -- Reset -- + ----------- + + procedure Reset (Gen : out Generator) is + begin + Reset (Gen.Rep); + Gen.Have_Gaussian := False; + end Reset; + + procedure Reset + (Gen : out Generator; + Initiator : Initialization_Vector) + is + begin + Reset (Gen.Rep, Initiator); + Gen.Have_Gaussian := False; + end Reset; + + procedure Reset + (Gen : out Generator; + Initiator : Interfaces.Integer_32) + is + begin + Reset (Gen.Rep, Initiator); + Gen.Have_Gaussian := False; + end Reset; + + procedure Reset + (Gen : out Generator; + Initiator : Interfaces.Unsigned_32) + is + begin + Reset (Gen.Rep, Initiator); + Gen.Have_Gaussian := False; + end Reset; + + procedure Reset + (Gen : out Generator; + Initiator : Integer) + is + begin + Reset (Gen.Rep, Initiator); + Gen.Have_Gaussian := False; + end Reset; + + procedure Reset + (Gen : out Generator; + From_State : Generator) + is + begin + Reset (Gen.Rep, From_State.Rep); + Gen.Have_Gaussian := From_State.Have_Gaussian; + Gen.Next_Gaussian := From_State.Next_Gaussian; + end Reset; + + Frac_Scale : constant Long_Float := + Long_Float + (Long_Float'Machine_Radix) ** Long_Float'Machine_Mantissa; + + function Val64 (Image : String) return Integer_64; + -- Renames Integer64'Value + -- We cannot use a 'renames Integer64'Value' since for some strange + -- reason, this requires a dependency on s-auxdec.ads which not all + -- run-times support ??? + + function Val64 (Image : String) return Integer_64 is + begin + return Integer_64'Value (Image); + end Val64; + + procedure Reset + (Gen : out Generator; + From_Image : String) + is + F0 : constant Integer := From_Image'First; + T0 : constant Integer := From_Image'First + Sys_Max_Image_Width; + + begin + Reset (Gen.Rep, From_Image (F0 .. F0 + Sys_Max_Image_Width)); + + if From_Image (T0 + 1) = '1' then + Gen.Have_Gaussian := True; + Gen.Next_Gaussian := + Long_Float (Val64 (From_Image (T0 + 3 .. T0 + 23))) / Frac_Scale + * Long_Float (Long_Float'Machine_Radix) + ** Integer (Val64 (From_Image (T0 + 25 .. From_Image'Last))); + else + Gen.Have_Gaussian := False; + end if; + end Reset; + + ----------- + -- Image -- + ----------- + + function Image (Gen : Generator) return String is + Result : Image_String; + + begin + Result := (others => ' '); + Result (1 .. Sys_Max_Image_Width) := Image (Gen.Rep); + + if Gen.Have_Gaussian then + Result (Sys_Max_Image_Width + 2) := '1'; + Insert_Image (Result, Sys_Max_Image_Width + 4, + Integer_64 (Long_Float'Fraction (Gen.Next_Gaussian) + * Frac_Scale)); + Insert_Image (Result, Sys_Max_Image_Width + 24, + Integer_64 (Long_Float'Exponent (Gen.Next_Gaussian))); + + else + Result (Sys_Max_Image_Width + 2) := '0'; + end if; + + return Result; + end Image; + +end GNAT.Random_Numbers; |