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Groups > comp.lang.java.programmer > #25105

Re: Autoboxing and Performance ?

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Arne Vajhøj schrieb:
> He made some comments to you that explained that you
> you had forgotten about the escape analysis
> capability in your explanation.

It seems to me that Lew has sometimes no clue what he is
writing about. For example I wrote:

> Most probably the generated code for unboxing/boxing will
> use Integer.intValue() to access the value and Integer.valueOf()
> to create a new object.

Which refers to Java byte code generation.

Then Lew wrote:

 > Assuming HotSpot doesn't entirely optimize away the object references.

Which refers to code generate by the JVM from the
given Java byte code. So I didn't say something wrong.

Then Lew wrote:

 > It is very dangerous to make performance claims about
 > Java based on _a priori_ reasoning.

I could ask him the same about his Hotspot escape analysis
claim. Where is HIS evidence? Under what load? What percentage
of code is subject to the Hotspot escape analysis? Etc..

Since the OPs code is main() and not some heavily used
loop, most likely no Hotspot compilation will kick in at
all. So most likely the code will be executed as I
described it:

> In your present case thus, already for 99 an object from the
> cache is fetched, and then for 100 also an object from the cache
> is fetched, thus not involving any single heap allocation.

I am willingly to retract my claim if some counter evidence
can be provided.

Bye

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Autoboxing and Performance ? Peter Olcott <OCR4Screen> - 2013-08-20 05:15 -0500
  Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-20 12:20 +0200
    Re: Autoboxing and Performance ? Peter Olcott <OCR4Screen> - 2013-08-20 05:33 -0500
      Re: Autoboxing and Performance ? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2013-08-20 10:43 +0000
        Re: Autoboxing and Performance ? Peter Olcott <OCR4Screen> - 2013-08-20 06:04 -0500
          Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-20 08:08 -0400
          Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-20 20:15 -0400
      Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-20 20:12 -0400
      Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-21 03:52 +0300
        Re: Autoboxing and Performance ? Sebastian <news@seyweiler.dyndns.org> - 2013-08-21 07:27 +0200
          Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-21 18:43 -0400
            Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-22 08:08 +0300
          Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-22 07:56 +0300
            Re: Autoboxing and Performance ? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-08-22 10:51 -0700
              Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-22 19:36 +0000
                Re: Autoboxing and Performance ? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-08-22 13:01 -0700
                Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-22 21:19 +0000
                Re: Autoboxing and Performance ? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-08-22 14:39 -0700
                Re: Autoboxing and Performance ? markspace <markspace@nospam.nospam> - 2013-08-22 19:50 -0700
                Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-23 23:16 +0000
                Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-24 17:20 +0300
                Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-23 11:08 -0700
                Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-23 22:52 +0200
                Re: Autoboxing and Performance ? Jim Gibson <jimsgibson@gmail.com> - 2013-08-23 16:38 -0700
                Re: Autoboxing and Performance ? "John B. Matthews" <nospam@nospam.invalid> - 2013-08-23 06:17 -0400
                Re: Autoboxing and Performance ? Jeff Higgins <jeff@invalid.invalid> - 2013-08-23 17:25 -0400
                Re: Autoboxing and Performance ? Jeff Higgins <jeff@invalid.invalid> - 2013-08-25 18:34 -0400
                Re: Autoboxing and Performance ? Jeff Higgins <jeff@invalid.invalid> - 2013-08-28 10:52 -0400
                Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-23 23:37 +0000
        Re: Autoboxing and Performance ? Robert Klemme <shortcutter@googlemail.com> - 2013-08-26 19:33 +0200
          Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-29 10:09 +0300
            Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-29 14:14 +0200
      Re: Autoboxing and Performance ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-08-29 21:28 -0300
  Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-20 20:03 +0200
    Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-20 16:23 -0700
      Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-21 11:51 +0200
        Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-21 08:39 -0700
          Re: Autoboxing and Performance ? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-08-21 16:51 +0100
        Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-21 19:19 -0400
          Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-22 09:49 +0200
    Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-21 11:54 +0200
  Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-20 20:06 -0400
    Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-20 21:19 -0400
      Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-21 10:05 +0200
        Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-21 07:19 -0400
          Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-22 00:18 +0200
            Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-21 19:58 -0400
        Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-21 08:36 -0700
      Re: Autoboxing and Performance ? taqmcg@gmail.com - 2013-08-21 09:37 -0700
  Re: Autoboxing and Performance ? Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2013-08-20 23:28 -0500
  Re: Autoboxing and Performance ? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-08-21 10:09 +0100
    Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-21 19:04 -0400
      Re: Autoboxing and Performance ? Arivald <NOSPAMarivald@interia.pl> - 2013-08-22 07:39 +0200
  Re: Autoboxing and Performance ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-08-29 01:42 -0300

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