RE: New portion of improvements for Dual-Pivot Quicksort

[Dmytro Sheyko]

Hi Remi,

I believe that it is up to javac to generate compact and 
interpretation-efficient bytecode.
But anyway the first case seems to as acceptable as the second one. So I don't 
care which style is used (of course, if it's consistent).

Thanks,
Dmytro Sheyko

Date: Wed, 19 May 2010 12:09:57 +0200
From: fo...@univ-mlv.fr
To: core-libs-dev@openjdk.java.net
Subject: Re: New portion of improvements for Dual-Pivot Quicksort






  


Le 19/05/2010 11:02, Dmytro Sheyko a écrit :

  Vladimir,

  

I can see that you changed sortNegZeroAndNaN(float[]...) but probably
forgot to change sortNegZeroAndNaN(double[]...).

  

You really puzzled me with failed testcase and note that sorting
algorithm (without special attention to zeros) generally may change
number of negative zeros.

I will provide my comments later.

  

As for counting sort, I think we should use single format style over
the file (unless we have valuable reason not to do this). I mean to
choose

1)

        if (toIndex - fromIndex >
COUNTING_SORT_THRESHOLD_FOR_SHORT_OR_CHAR) {

            countingSort(a, fromIndex, toIndex);

            return;

        }

        sort(a, fromIndex, toIndex - 1, true);

2)

        if (toIndex - fromIndex >
COUNTING_SORT_THRESHOLD_FOR_SHORT_OR_CHAR) {

            countingSort(a, fromIndex, toIndex);

        } else {

            sort(a, fromIndex, toIndex - 1, true);

        }

I prefer the second one.

  

Thanks a lot,

Dmytro Sheyko




But the former have a more compact bytecode representation (return vs
goto) and avoid an unecessary jump for interpreters.



Rémi
                                          
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