Re: Static superinstructions(was: OT (slightly) What is the "best" ...)

From	"Rod Pemberton" <do_not_have@notemailnotq.cpm>
Newsgroups	comp.lang.forth
Subject	Re: Static superinstructions(was: OT (slightly) What is the "best" ...)
Date	2013-07-07 11:32 -0400
Organization	Aioe.org NNTP Server
Message-ID	<krc1do$os4$1@speranza.aioe.org> (permalink)
References	(7 earlier) <e8ec1234-c381-45fb-9466-c21b1013c72d@googlegroups.com> <8vCdnYeb3YfLD0_MnZ2dnUVZ_s6dnZ2d@supernews.com> <dc1b1c8b-3ea7-4ea6-9ff5-9f0edc7c2d48@googlegroups.com> <kr0qmq$4vd$1@speranza.aioe.org> <2013Jul3.163310@mips.complang.tuwien.ac.at>

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"Anton Ertl" <anton@mips.complang.tuwien.ac.at> wrote in message
news:2013Jul3.163310@mips.complang.tuwien.ac.at...
> "Rod Pemberton" <do_not_have@notemailnotq.cpm> writes:

> >> For example: OVER_+ should be a primitive. This is
> >> generally faster than OVER followed by +, and it
> >> halves the memory usage in the threaded code.
> >
> >The probability of any Forth instruction being executed is
> >really low, even for the heavy usage instructions, of which
> >there are only a few.  See the work by Philip Koopman or
> >Anton Ertl on instruction frequencies.
>
> Well, looking at <[link]>,
> primitives like ;s (EXIT), col: (colon definition entry routine),
> @, ?branch (if), lit, var: (CREATEd word entry routine), dup,
> user:, swap, + are pretty frequent, constituting between 3% (+)
> and 13% (;s) of all NEXTs.  There are also some frequent
> dynamic sequences, in particular col: col: (4.5%), user:
> @ (2.7%), @ ;s (2.7%), ;s ;s (2.7%), var: @ (2.5%).  "over +"
> is relatively rare, though, at 0.14% of the frequency of NEXT.
>

3% is frequent?  30% is frequent.  Yes, 3% is frequent relative to
the non-frequent instructions.

> When writing the papers I used this feature for up to 1600
> superinstructions.  In production, we currently use only 13
> superinstructions, for the following reasons: 1) Dynamic
> superinstructions give more speedup than static
> superinstructions, and once they are there, static
> superinstructions (even if you have a lot)
> provide little additional benefit (see below).

Hopefully, Hugh read what you just said about static
superinstructions.

> [SNIP]
> Concerning the benefit of having many superinstructions,
> most of it is due to having more indirect branches in the
> interpreter, leading to better indirect branch prediction.

It seems like you're solving the wrong problem, or solving it
indirectly.  I.e., shouldn't you find a way optimize the branches
without creating superinstructions?

> [SNIP]

Most of what you mentioned seemed to be ways to implement
rudimentary code optimization.


Rod Pemberton.

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Re: OT (slightly) What is the "best" processor for a new project? rickman <gnuarm@gmail.com> - 2013-06-18 00:01 -0400
  Re: OT (slightly) What is the "best" processor for a new project? Bernd Paysan <bernd.paysan@gmx.de> - 2013-06-19 15:33 +0200
    Re: OT (slightly) What is the "best" processor for a new project? rickman <gnuarm@gmail.com> - 2013-06-19 17:25 -0400
      Re: OT (slightly) What is the "best" processor for a new project? Hugh Aguilar <hughaguilar96@yahoo.com> - 2013-06-19 17:00 -0700
        Re: OT (slightly) What is the "best" processor for a new project? rickman <gnuarm@gmail.com> - 2013-06-20 18:35 -0400
    Re: OT (slightly) What is the "best" processor for a new project? Hugh Aguilar <hughaguilar96@yahoo.com> - 2013-06-19 17:38 -0700
      Re: OT (slightly) What is the "best" processor for a new project? Bernd Paysan <bernd.paysan@gmx.de> - 2013-06-20 12:51 +0200
        Re: OT (slightly) What is the "best" processor for a new project? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-06-20 15:28 +0000
        Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-06-20 18:39 -0700
          Re: OT (slightly) What is the "best" processor for a new project? Bernd Paysan <bernd.paysan@gmx.de> - 2013-06-21 14:50 +0200
            Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-06-22 18:56 -0700
              Re: OT (slightly) What is the "best" processor for a new project? "WJ" <w_a_x_man@yahoo.com> - 2013-06-23 02:35 +0000
                Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-06-22 20:48 -0700
              Re: OT (slightly) What is the "best" processor for a new project? Bernd Paysan <bernd.paysan@gmx.de> - 2013-06-23 14:49 +0200
                Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-06-26 18:08 -0700
                Re: OT (slightly) What is the "best" processor for a new project? Bernd Paysan <bernd.paysan@gmx.de> - 2013-06-27 16:32 +0200
                Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-06-30 10:10 -0700
                Re: OT (slightly) What is the "best" processor for a new project? rickman <gnuarm@gmail.com> - 2013-06-30 15:18 -0400
                Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-06-30 16:01 -0700
                Re: OT (slightly) What is the "best" processor for a new project? rickman <gnuarm@gmail.com> - 2013-06-30 20:22 -0400
                Re: OT (slightly) What is the "best" processor for a new project? Bernd Paysan <bernd.paysan@gmx.de> - 2013-06-30 21:22 +0200
                Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-06-30 15:52 -0700
                Re: OT (slightly) What is the "best" processor for a new project? Bernd Paysan <bernd.paysan@gmx.de> - 2013-07-01 02:02 +0200
                Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-06-30 19:25 -0700
                Re: OT (slightly) What is the "best" processor for a new project? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-07-01 02:34 -0500
                Re: OT (slightly) What is the "best" processor for a new project? rickman <gnuarm@gmail.com> - 2013-07-01 16:26 -0400
                Re: OT (slightly) What is the "best" processor for a new project? Bernd Paysan <bernd.paysan@gmx.de> - 2013-07-01 23:08 +0200
                Re: OT (slightly) What is the "best" processor for a new project? rickman <gnuarm@gmail.com> - 2013-07-01 18:10 -0400
                Re: OT (slightly) What is the "best" processor for a new project? "Elizabeth D. Rather" <erather@forth.com> - 2013-07-01 12:35 -1000
                Re: OT (slightly) What is the "best" processor for a new project? rickman <gnuarm@gmail.com> - 2013-07-01 18:42 -0400
                Re: OT (slightly) What is the "best" processor for a new project? "Elizabeth D. Rather" <erather@forth.com> - 2013-07-01 13:03 -1000
                Re: OT (slightly) What is the "best" processor for a new project? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-07-02 07:20 +0000
                Re: OT (slightly) What is the "best" processor for a new project? "Elizabeth D. Rather" <erather@forth.com> - 2013-07-02 07:38 -1000
                Re: OT (slightly) What is the "best" processor for a new project? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-07-02 07:24 +0000
                Re: OT (slightly) What is the "best" processor for a new project? Bernd Paysan <bernd.paysan@gmx.de> - 2013-07-02 13:02 +0200
                Re: OT (slightly) What is the "best" processor for a new project? "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-07-02 05:58 -0400
                Re: OT (slightly) What is the "best" processor for a new project? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-07-02 03:34 -0500
                Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-07-01 20:01 -0700
                Re: OT (slightly) What is the "best" processor for a new project? "WJ" <w_a_x_man@yahoo.com> - 2013-07-02 04:43 +0000
                Re: OT (slightly) What is the "best" processor for a new project? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-07-02 03:41 -0500
                Re: OT (slightly) What is the "best" processor for a new project? "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-07-02 06:09 -0400
                Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-07-02 13:51 -0700
                Re: OT (slightly) What is the "best" processor for a new project? daveyrotten <danw8804@gmail.com> - 2013-07-02 14:37 -0700
                Re: OT (slightly) What is the "best" processor for a new project? daveyrotten <danw8804@gmail.com> - 2013-07-02 14:56 -0700
                Re: OT (slightly) What is the "best" processor for a new project? Bernd Paysan <bernd.paysan@gmx.de> - 2013-07-03 00:30 +0200
                Re: OT (slightly) What is the "best" processor for a new project? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-07-03 02:19 -0500
                Re: OT (slightly) What is the "best" processor for a new project? "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-07-03 05:18 -0400
                Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-07-03 18:10 -0700
                Re: OT (slightly) What is the "best" processor for a new project? "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-07-03 05:30 -0400
                Static superinstructions(was: OT (slightly) What is the "best" ...) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-07-03 14:33 +0000
                Re: Static superinstructions(was: OT (slightly) What is the "best" ...) Bernd Paysan <bernd.paysan@gmx.de> - 2013-07-04 00:41 +0200
                Re: Static superinstructions(was: OT (slightly) What is the "best" ...) "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-07-07 11:32 -0400
                Re: OT (slightly) What is the "best" processor for a new project? hughaguilar96@yahoo.com - 2013-07-03 18:31 -0700
                Re: OT (slightly) What is the "best" processor for a new project? "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-07-07 11:28 -0400
                Re: OT (slightly) What is the "best" processor for a new project? rickman <gnuarm@gmail.com> - 2013-07-02 16:44 -0400
                Re: OT (slightly) What is the "best" processor for a new project? "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-07-02 05:56 -0400
                Re: OT (slightly) What is the "best" processor for a new project? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-07-02 05:58 -0500
                Re: OT (slightly) What is the "best" processor for a new project? "Rod Pemberton" <do_not_have@notemailnotq.cpm> - 2013-07-03 05:57 -0400
                Re: OT (slightly) What is the "best" processor for a new project? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-07-03 06:43 -0500
                Re: OT (slightly) What is the "best" processor for a new project? rickman <gnuarm@gmail.com> - 2013-06-30 20:29 -0400
                Re: OT (slightly) What is the "best" processor for a new project? rickman <gnuarm@gmail.com> - 2013-06-27 10:58 -0400

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