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Diffstat (limited to 'gcc/ada/a-cgcaso.adb')
| -rw-r--r-- | gcc/ada/a-cgcaso.adb | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/gcc/ada/a-cgcaso.adb b/gcc/ada/a-cgcaso.adb new file mode 100644 index 000000000..646137719 --- /dev/null +++ b/gcc/ada/a-cgcaso.adb @@ -0,0 +1,121 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT LIBRARY COMPONENTS -- +-- -- +-- ADA.CONTAINERS.GENERIC_CONSTRAINED_ARRAY_SORT -- +-- -- +-- B o d y -- +-- -- +-- 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 -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- This unit was originally developed by Matthew J Heaney. -- +------------------------------------------------------------------------------ + +-- This algorithm was adapted from GNAT.Heap_Sort_G (see g-hesorg.ad[sb]) + +with System; + +procedure Ada.Containers.Generic_Constrained_Array_Sort + (Container : in out Array_Type) +is + type T is range System.Min_Int .. System.Max_Int; + + function To_Index (J : T) return Index_Type; + pragma Inline (To_Index); + + procedure Sift (S : T); + + A : Array_Type renames Container; + + -------------- + -- To_Index -- + -------------- + + function To_Index (J : T) return Index_Type is + K : constant T'Base := Index_Type'Pos (A'First) + J - T'(1); + begin + return Index_Type'Val (K); + end To_Index; + + Max : T := A'Length; + Temp : Element_Type; + + ---------- + -- Sift -- + ---------- + + procedure Sift (S : T) is + C : T := S; + Son : T; + + begin + loop + Son := 2 * C; + + exit when Son > Max; + + declare + Son_Index : Index_Type := To_Index (Son); + + begin + if Son < Max then + if A (Son_Index) < A (Index_Type'Succ (Son_Index)) then + Son := Son + 1; + Son_Index := Index_Type'Succ (Son_Index); + end if; + end if; + + A (To_Index (C)) := A (Son_Index); -- Move (Son, C); + end; + + C := Son; + end loop; + + while C /= S loop + declare + Father : constant T := C / 2; + begin + if A (To_Index (Father)) < Temp then -- Lt (Father, 0) + A (To_Index (C)) := A (To_Index (Father)); -- Move (Father, C) + C := Father; + else + exit; + end if; + end; + end loop; + + A (To_Index (C)) := Temp; -- Move (0, C); + end Sift; + +-- Start of processing for Generic_Constrained_Array_Sort + +begin + for J in reverse 1 .. Max / 2 loop + Temp := Container (To_Index (J)); -- Move (J, 0); + Sift (J); + end loop; + + while Max > 1 loop + Temp := A (To_Index (Max)); -- Move (Max, 0); + A (To_Index (Max)) := A (A'First); -- Move (1, Max); + + Max := Max - 1; + Sift (1); + end loop; +end Ada.Containers.Generic_Constrained_Array_Sort; |