X-Git-Url: https://oss.titaniummirror.com/gitweb?a=blobdiff_plain;f=gcc%2Fada%2Fg-hesorg.adb;fp=gcc%2Fada%2Fg-hesorg.adb;h=0000000000000000000000000000000000000000;hb=6fed43773c9b0ce596dca5686f37ac3fc0fa11c0;hp=0b58d9dc9c4ac60583944762859033f9fd014bfd;hpb=27b11d56b743098deb193d510b337ba22dc52e5c;p=msp430-gcc.git diff --git a/gcc/ada/g-hesorg.adb b/gcc/ada/g-hesorg.adb deleted file mode 100644 index 0b58d9dc..00000000 --- a/gcc/ada/g-hesorg.adb +++ /dev/null @@ -1,135 +0,0 @@ ------------------------------------------------------------------------------- --- -- --- GNAT RUNTIME COMPONENTS -- --- -- --- G N A T . H E A P _ S O R T _ G -- --- -- --- B o d y -- --- -- --- $Revision: 1.1.16.1 $ --- -- --- Copyright (C) 1995-1999 Ada Core Technologies, 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 is maintained by Ada Core Technologies Inc (http://www.gnat.com). -- --- -- ------------------------------------------------------------------------------- - -package body GNAT.Heap_Sort_G is - - ---------- - -- Sort -- - ---------- - - -- We are using the classical heapsort algorithm (i.e. Floyd's Treesort3) - -- as described by Knuth ("The Art of Programming", Volume III, first - -- edition, section 5.2.3, p. 145-147) with the modification that is - -- mentioned in exercise 18. For more details on this algorithm, see - -- Robert B. K. Dewar PhD thesis "The use of Computers in the X-ray - -- Phase Problem". University of Chicago, 1968, which was the first - -- publication of the modification, which reduces the number of compares - -- from 2NlogN to NlogN. - - procedure Sort (N : Natural) is - - Max : Natural := N; - -- Current Max index in tree being sifted - - procedure Sift (S : Positive); - -- This procedure sifts up node S, i.e. converts the subtree rooted - -- at node S into a heap, given the precondition that any sons of - -- S are already heaps. On entry, the contents of node S is found - -- in the temporary (index 0), the actual contents of node S on - -- entry are irrelevant. This is just a minor optimization to avoid - -- what would otherwise be two junk moves in phase two of the sort. - - procedure Sift (S : Positive) is - C : Positive := S; - Son : Positive; - Father : Positive; - - begin - -- This is where the optimization is done, normally we would do a - -- comparison at each stage between the current node and the larger - -- of the two sons, and continue the sift only if the current node - -- was less than this maximum. In this modified optimized version, - -- we assume that the current node will be less than the larger - -- son, and unconditionally sift up. Then when we get to the bottom - -- of the tree, we check parents to make sure that we did not make - -- a mistake. This roughly cuts the number of comparisions in half, - -- since it is almost always the case that our assumption is correct. - - -- Loop to pull up larger sons - - loop - Son := 2 * C; - exit when Son > Max; - - if Son < Max and then Lt (Son, Son + 1) then - Son := Son + 1; - end if; - - Move (Son, C); - C := Son; - end loop; - - -- Loop to check fathers - - while C /= S loop - Father := C / 2; - - if Lt (Father, 0) then - Move (Father, C); - C := Father; - else - exit; - end if; - end loop; - - -- Last step is to pop the sifted node into place - - Move (0, C); - end Sift; - - -- Start of processing for Sort - - begin - -- Phase one of heapsort is to build the heap. This is done by - -- sifting nodes N/2 .. 1 in sequence. - - for J in reverse 1 .. N / 2 loop - Move (J, 0); - Sift (J); - end loop; - - -- In phase 2, the largest node is moved to end, reducing the size - -- of the tree by one, and the displaced node is sifted down from - -- the top, so that the largest node is again at the top. - - while Max > 1 loop - Move (Max, 0); - Move (1, Max); - Max := Max - 1; - Sift (1); - end loop; - - end Sort; - -end GNAT.Heap_Sort_G;