Re: How many x86 instructions?

From	Robert Redelmeier <redelm@ev1.net.invalid>
Newsgroups	comp.sys.intel, comp.sys.ibm.pc.hardware.chips, alt.windows7.general
Subject	Re: How many x86 instructions?
Date	2014-02-22 02:16 +0000
Organization	Aioe.org NNTP Server
Message-ID	<le919q$ph$1@speranza.aioe.org> (permalink)
References	<53068f25$1@news.bnb-lp.com> <le69i5$2vq$1@news.albasani.net> <5306baeb$1@news.bnb-lp.com> <le7ng5$jfq$1@speranza.aioe.org> <5307a5d9$1@news.bnb-lp.com>

Cross-posted to 3 groups.

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In comp.sys.ibm.pc.hardware.chips Yousuf Khan <bbbl67@spammenot.yahoo.com> wrote in part:
> On 21/02/2014 9:23 AM, Robert Redelmeier wrote:
>> In comp.sys.ibm.pc.hardware.chips Yousuf Khan <bbbl67@spammenot.yahoo.com> wrote in part:
>>> But it goes to show why the age of compilers is well and
>>> truly upon us, there's no human way to keep track of these
>>> machine language instructions. Compilers just use a subset,
>>> and just repeat those instructions over and over again.
>>
>> Hate to break it to you, but you are behind the times.  Compilers
>> are passe' -- "modern" systems use interpreters like JIT Java.
>>
>> How else you you think Android gets Apps to run on the dogs-breakfast
>> of ARM processors out there?  It is [nearly] all interpreted Java.
>> So much so that Dell can get 'roid Apps to run on its x86 tablet!
>> (AFAIK, iOS still runs compiled Apps prob'cuz Apple _hatez_ Oracle)
> 
> Apparently, even Java byte code is compiled before it is run on a 
> different type of virtual machine than its own Java VM. Can't use Java 
> directly on Android:
> 
> "There is no Java Virtual Machine in the Android platform. Java bytecode 
> is not executed. Instead Java classes are compiled into a proprietary 
> bytecode format and run on Dalvik, a specialized virtual machine (VM) 
> designed specifically for Android. Unlike Java VMs, which are stack 
> machines, the Dalvik VM is a register-based architecture.
> 
> Because the bytecode loaded by the Dalvik virtual machine is not Java 
> bytecode, and of the specific way Dalvik load classes, it is not 
> possible to load Java libraries packages as jar files, and even a 
> specific logic must be used to load Android libraries (specifically the 
> content of the underlying dex file must be copied in the application 
> private internal storage area, before being able to be loaded).[2]"
> 
> Comparison of Java and Android API - Wikipedia, the free encyclopedia
> http://en.wikipedia.org/wiki/Comparison_of_Java_and_Android_API
 

Thanks you for the additional details.  "precompiled" makes some sense
-- why waste all that time parsing ASCII?  Dalvik would of course
have to be customized for the flavor of ARM it was installed on.

Dalvik being a register-based VM also makes some sense for
ARMs with more registers.  x86 has a blazing fast data L1
that reduces the stack penalty, often to zero.  I wonder how
Dell implemented Dalvik on the Venue?


-- Robert

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Thread

How many x86 instructions? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2014-02-20 18:26 -0500
  Re: How many x86 instructions? Gene E. Bloch <blochxxxx@someplace.invalid> - 2014-02-20 17:19 -0800
    Re: How many x86 instructions? Gene E. Bloch <blochxxxx@someplace.invalid> - 2014-02-20 17:26 -0800
      Re: How many x86 instructions? Gene E. Bloch <blochxxxx@someplace.invalid> - 2014-02-20 17:29 -0800
    Re: How many x86 instructions? Gene E. Bloch <blochxxxx@someplace.invalid> - 2014-02-20 17:35 -0800
    Re: How many x86 instructions? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2014-02-20 21:33 -0500
      Re: How many x86 instructions? Gene E. Bloch <blochxxxx@someplace.invalid> - 2014-02-20 19:46 -0800
      Re: How many x86 instructions? Gene E. Bloch <blochxxxx@someplace.invalid> - 2014-02-20 20:02 -0800
      Re: How many x86 instructions? Paul <nospam@needed.com> - 2014-02-20 23:21 -0500
        Re: How many x86 instructions? Gene E. Bloch <blochxxxx@someplace.invalid> - 2014-02-20 21:23 -0800
        Re: How many x86 instructions? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2014-02-21 00:55 -0500
          Re: How many x86 instructions? "Stanley Daniel de Liver" <admin@127.0.0.1> - 2014-04-25 10:54 +0100
            Re: How many x86 instructions? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2014-04-25 20:58 -0400
              Re: How many x86 instructions? "Stanley Daniel de Liver" <admin@127.0.0.1> - 2014-04-26 11:29 +0100
      Re: How many x86 instructions? Robert Redelmeier <redelm@ev1.net.invalid> - 2014-02-21 14:23 +0000
        Re: How many x86 instructions? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2014-02-21 14:15 -0500
          Re: How many x86 instructions? Gene E. Bloch <blochxxxx@someplace.invalid> - 2014-02-21 11:34 -0800
            Re: How many x86 instructions? charlie <cdknospam@msn.com> - 2014-02-23 10:14 -0500
              Re: How many x86 instructions? "J. P. Gilliver (John)" <G6JPG@soft255.demon.co.uk> - 2014-02-23 16:37 +0000
                Re: How many x86 instructions? charlie <cdknospam@msn.com> - 2014-02-23 17:41 -0500
                Re: How many x86 instructions? BillW50 <BillW50@aol.kom> - 2014-02-23 17:15 -0600
                Re: How many x86 instructions? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2014-02-23 19:30 -0500
                Re: How many x86 instructions? Gene E. Bloch <blochxxxx@someplace.invalid> - 2014-02-24 12:11 -0800
                Re: How many x86 instructions? Jason <jason_warren@ieee.org> - 2014-02-24 18:41 -0500
                Re: How many x86 instructions? krw@attt.bizz - 2014-02-23 19:34 -0500
                Re: How many x86 instructions? charlie <cdknospam@msn.com> - 2014-02-24 04:42 -0500
                Re: How many x86 instructions? Gene E. Bloch <blochxxxx@someplace.invalid> - 2014-02-23 15:45 -0800
                Re: How many x86 instructions? BillW50 <BillW50@aol.kom> - 2014-02-23 17:49 -0600
          Re: How many x86 instructions? Char Jackson <none@none.invalid> - 2014-02-21 19:03 -0600
          Re: How many x86 instructions? Robert Redelmeier <redelm@ev1.net.invalid> - 2014-02-22 02:16 +0000
            Re: How many x86 instructions? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2014-02-21 21:32 -0500
        Re: How many x86 instructions? Jason <jason_warren@ieee.org> - 2014-02-23 23:21 -0500
          Re: How many x86 instructions? krw@attt.bizz - 2014-02-24 13:02 -0500
            Re: How many x86 instructions? Jason <jason_warren@ieee.org> - 2014-02-24 13:38 -0500
              Re: How many x86 instructions? krw@attt.bizz - 2014-02-24 14:09 -0500
                Re: How many x86 instructions? Jason <jason_warren@ieee.org> - 2014-02-24 16:35 -0500
            Re: How many x86 instructions? pedro1492@lycos.com - 2014-03-28 19:50 -0700
              Re: How many x86 instructions? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2014-04-02 09:47 -0400
          Re: How many x86 instructions? Robert Redelmeier <redelm@ev1.net.invalid> - 2014-02-25 00:35 +0000
            Re: How many x86 instructions? John Doe <jdoe@usenetlove.invalid> - 2014-04-25 03:33 +0000
  Re: How many x86 instructions? "Jim" <gtfo@stfu.invalid> - 2014-02-27 01:28 -0500

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