Re: Green Compiler ?

From	Hans-Peter Diettrich <DrDiettrich1@aol.com>
Newsgroups	comp.compilers
Subject	Re: Green Compiler ?
Date	2012-12-30 08:14 +0100
Organization	Compilers Central
Message-ID	<12-12-037@comp.compilers> (permalink)
References	<12-12-010@comp.compilers> <12-12-012@comp.compilers> <12-12-022@comp.compilers> <12-12-028@comp.compilers> <12-12-034@comp.compilers>

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Peter Dassow schrieb:
> On 28.12.2012 08:35, Hans-Peter Diettrich wrote:
>>
>> Please note that most CMOS processor power consumption results from
>> switching (stray) capacities, and only a small percentage for leak
>> currents. E.g. a register or gate consumes such power whenever a bit is
>> changed, and almost nothing when it has reached an stable state.
>>
> So using extensively registers instead of "conventional" memory (e.g.
> DDR-RAM, memory outside a CPU) will save energy (if equal functionality
> is given) ?

I don't see a relationship here, except that external memory is slow
and [in x86] a couple of caches and address translations are involved
in reading from RAM. But registers are a very scarce resource, so that
frequent loading from memory is hardly avoidable. Register usage is
already optimized by every (good) compiler, reducing runtime and power
consuption at the same time. This was a very narrow bottleneck of the
IA-32 architecture, until the 64 bit (AMD) model increased the number
of registers considerably (16 addressable, of 128 [256?] shadow
registers).  The CPU computation circuitry and usage is the same,
regardless of the operand sources.

DoDi

Thread

Green Compiler ? Abid <abidmuslim@gmail.com> - 2012-12-20 02:00 -0800
  Re: Green Compiler ? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-23 08:18 +0000
    Re: Green Compiler ? Peter Dassow <z80eu@arcor.de> - 2012-12-26 19:31 +0100
      Re: Green Compiler ? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-28 03:09 +0000
      Re: Green Compiler ? Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2012-12-28 08:35 +0100
        Re: Green Compiler ? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-28 16:14 +0000
        Re: Green Compiler ? Peter Dassow <z80eu@arcor.de> - 2012-12-29 09:35 +0100
          Re: Green Compiler ? Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2012-12-30 08:14 +0100
            Re: Green Compiler ? George Neuner <gneuner2@comcast.net> - 2012-12-31 01:24 -0500
              Re: Green Compiler ? "Jonathan Thornburg" <jthorn@astro.indiana.edu> - 2013-01-02 04:09 +0000
                Re: Green Compiler ? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-01-02 18:29 +0000
              Re: Green Compiler ? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-01-02 05:11 +0000
              Re: Green Compiler ? Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2013-01-02 07:29 +0100
                Re: Green Compiler ? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-01-02 19:52 +0000
                Re: Green Compiler ? "Charles Richmond" <numerist@aquaporin4.com> - 2013-01-04 08:59 -0600
  Re: Green Compiler ? "Nils M Holm" <nmh@t3x.org> - 2012-12-23 10:01 +0100
    Re: Green Compiler ? Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2012-12-24 05:16 +0100
    Re: Green Compiler ? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-12-27 13:36 +0000
      Re: Green Compiler ? "Nils M Holm" <nmh@t3x.org> - 2012-12-28 09:11 +0100
        Re: Green Compiler ? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-12-28 16:57 +0000
        Re: Green Compiler ? George Neuner <gneuner2@comcast.net> - 2012-12-28 12:57 -0500
          Re: Green Compiler ? "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2012-12-30 09:22 +0100
    Re: Green Compiler ? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-12-27 21:59 -0600
  Re: Green Compiler ? Walter Banks <walter@bytecraft.com> - 2012-12-28 10:42 -0500

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