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Re: Would green arrays produce something with a web browser? like a cheap appliance?

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David Kuehling wrote:
> But doesn't accumulation come for free?  I.e. if one multiplcation
> step +* is (test bit, shift left, add conditionally), and you need to
> accumulate, you just start with some value X instead of initializing
> to zero.

+* can do something like 18*18+18 (bits), but not 18*18+36. And to 
generate 36*36+72 (36 bit MAC), you would even need 18*18+72 to make 
this work without overhead.

> I though that this was the reason why all those DSPs include MAC
> operations.  The only downside is that you need 3 inputs to the
> operation, so more data busses and more read ports into the register
> file.

DSPs have parallel multipliers, where you indeed have ws*ws+dws (ws=word 
size, dws=double word size) as one operation, often single-
cylce/pipelined with one op per cycle.

-- 
Bernd Paysan
"If you want it done right, you have to do it yourself"
http://bernd-paysan.de/

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Re: Would green arrays produce something with a web browser? like a cheap appliance? Bernd Paysan <bernd.paysan@gmx.de> - 2012-02-07 16:35 +0100
  Re: Would green arrays produce something with a web browser? like a cheap appliance? rickman <gnuarm@gmail.com> - 2012-02-07 14:48 -0800
    Re: Would green arrays produce something with a web browser? like a cheap appliance? Paul Rubin <no.email@nospam.invalid> - 2012-02-07 17:07 -0800
      Re: Would green arrays produce something with a web browser? like a cheap appliance? rickman <gnuarm@gmail.com> - 2012-02-07 18:18 -0800
      Re: Would green arrays produce something with a web browser? like a cheap appliance? vandys@vsta.org - 2012-02-08 04:08 +0000
    Re: Would green arrays produce something with a web browser? like a cheap appliance? Bernd Paysan <bernd.paysan@gmx.de> - 2012-02-10 00:12 +0100
      Re: Would green arrays produce something with a web browser? like a cheap appliance? "Elizabeth D. Rather" <erather@forth.com> - 2012-02-09 14:59 -1000
        Re: Would green arrays produce something with a web browser? like a cheap appliance? Arnold Doray <invalid@invalid.com> - 2012-02-10 10:23 +0000
      Re: Would green arrays produce something with a web browser? like a cheap appliance? rickman <gnuarm@gmail.com> - 2012-02-09 19:58 -0800
        Re: Would green arrays produce something with a web browser? like a cheap appliance? Arnold Doray <invalid@invalid.com> - 2012-02-10 11:16 +0000
          Re: Would green arrays produce something with a web browser? like a cheap appliance? Bernd Paysan <bernd.paysan@gmx.de> - 2012-02-10 17:27 +0100
            Re: Would green arrays produce something with a web browser? like a cheap appliance? rickman <gnuarm@gmail.com> - 2012-02-16 13:12 -0800
              Re: Would green arrays produce something with a web browser? like a cheap appliance? Paul Rubin <no.email@nospam.invalid> - 2012-02-16 13:45 -0800
                Re: Would green arrays produce something with a web browser? like a cheap appliance? rickman <gnuarm@gmail.com> - 2012-02-20 16:35 -0800
                Re: Would green arrays produce something with a web browser? like a cheap appliance? vandys@vsta.org - 2012-02-21 01:03 +0000
                Re: Would green arrays produce something with a web browser? like a cheap appliance? Paul Rubin <no.email@nospam.invalid> - 2012-02-20 19:07 -0800
                Re: Would green arrays produce something with a web browser? like a cheap appliance? "Elizabeth D. Rather" <erather@forth.com> - 2012-02-20 19:15 -1000
                Re: Would green arrays produce something with a web browser? like a cheap appliance? Paul Rubin <no.email@nospam.invalid> - 2012-02-21 02:28 -0800
                Re: Would green arrays produce something with a web browser? like a cheap appliance? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-02-21 05:20 -0600
                Re: Would green arrays produce something with a web browser? like a cheap appliance? Paul Rubin <no.email@nospam.invalid> - 2012-02-22 02:31 -0800
                Re: Would green arrays produce something with a web browser? like a cheap appliance? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-02-22 05:03 -0600
                Re: Would green arrays produce something with a web browser? like a cheap appliance? Paul Rubin <no.email@nospam.invalid> - 2012-02-20 19:47 -0800
              Re: Would green arrays produce something with a web browser? like a cheap appliance? Bernd Paysan <bernd.paysan@gmx.de> - 2012-02-19 01:50 +0100
                Re: Would green arrays produce something with a web browser? like a cheap appliance? rickman <gnuarm@gmail.com> - 2012-02-20 16:47 -0800
                Re: Would green arrays produce something with a web browser? like a cheap appliance? Bernd Paysan <bernd.paysan@gmx.de> - 2012-02-21 02:27 +0100
                Re: Would green arrays produce something with a web browser? like a cheap appliance? forther <forther@gmail.com> - 2012-02-23 15:38 -0800
                Re: Would green arrays produce something with a web browser? like a cheap appliance? Bernd Paysan <bernd.paysan@gmx.de> - 2012-02-26 02:08 +0100
                Re: Would green arrays produce something with a web browser? like a cheap appliance? David Kuehling <dvdkhlng@gmx.de> - 2012-02-26 02:40 +0100
                Re: Would green arrays produce something with a web browser? like a cheap appliance? Bernd Paysan <bernd.paysan@gmx.de> - 2012-02-26 20:38 +0100
                Re: Would green arrays produce something with a web browser? like a cheap appliance? Paul Rubin <no.email@nospam.invalid> - 2012-02-26 13:44 -0800
                Re: Would green arrays produce something with a web browser? like a cheap appliance? forther <forther@gmail.com> - 2012-02-29 12:33 -0800
  Re: Would green arrays produce something with a web browser? like a cheap appliance? Arnold Doray <invalid@invalid.com> - 2012-02-10 11:02 +0000
    Re: Would green arrays produce something with a web browser? like a cheap appliance? Bernd Paysan <bernd.paysan@gmx.de> - 2012-02-10 17:54 +0100

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