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Re: Bitshifts and "And" vs Floor-division and Modular

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Date Fri, 07 Sep 2012 13:12:24 -0400
From Dave Angel <d@davea.name>
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Subject Re: Bitshifts and "And" vs Floor-division and Modular
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On 09/07/2012 12:59 PM, rusi wrote:
> On Sep 7, 9:32 am, Paul Rubin <no.em...@nospam.invalid> wrote:
>> rusi <rustompm...@gmail.com> writes:
>>> On an 8086/8088 a MUL (multiply) instruction was of the order of 100
>>> clocks ...  On most modern processors (after the pentium) the
>>> difference has mostly vanished.  I cant find a good data sheet to
>>> quote though
>> See http://www.agner.org/optimize/:
> Hey Thanks! Seems like a nice resource!  How on earth does he come up
> with the data though, when Intel does not publish it?

As he says on the home page, he measured the data himself.  Unclear how
repeatable such data may be, either due to environment or to multiple
versions of the processor, and from two vendors.

-- 

DaveA

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Thread

Bitshifts and "And" vs Floor-division and Modular jimbo1qaz <jimmyli1528@gmail.com> - 2012-09-06 17:01 -0700
  Re: Bitshifts and "And" vs Floor-division and Modular Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-09-07 01:30 +0100
    Re: Bitshifts and "And" vs Floor-division and Modular jimbo1qaz <jimmyli1528@gmail.com> - 2012-09-06 18:05 -0700
    Re: Bitshifts and "And" vs Floor-division and Modular jimbo1qaz <jimmyli1528@gmail.com> - 2012-09-06 18:05 -0700
  Re: Bitshifts and "And" vs Floor-division and Modular jimbo1qaz <jimmyli1528@gmail.com> - 2012-09-06 18:30 -0700
    Re: Bitshifts and "And" vs Floor-division and Modular Dave Angel <d@davea.name> - 2012-09-06 21:46 -0400
    Re: Bitshifts and "And" vs Floor-division and Modular Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-07 02:23 +0000
  Re: Bitshifts and "And" vs Floor-division and Modular Dave Angel <d@davea.name> - 2012-09-06 21:36 -0400
  Re: Bitshifts and "And" vs Floor-division and Modular Terry Reedy <tjreedy@udel.edu> - 2012-09-06 21:53 -0400
  Re: Bitshifts and "And" vs Floor-division and Modular Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-07 02:00 +0000
    Re: Bitshifts and "And" vs Floor-division and Modular Grant Edwards <invalid@invalid.invalid> - 2012-09-07 14:19 +0000
  Re: Bitshifts and "And" vs Floor-division and Modular rusi <rustompmody@gmail.com> - 2012-09-06 20:38 -0700
    Re: Bitshifts and "And" vs Floor-division and Modular Paul Rubin <no.email@nospam.invalid> - 2012-09-06 21:32 -0700
      Re: Bitshifts and "And" vs Floor-division and Modular rusi <rustompmody@gmail.com> - 2012-09-07 09:59 -0700
        Re: Bitshifts and "And" vs Floor-division and Modular Dave Angel <d@davea.name> - 2012-09-07 13:12 -0400

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