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Subject: Re: [boost] Flow-based programming library for Boost?
From: Dave Abrahams (dave_at_[hidden])
Date: 2012-12-15 17:20:58


on Wed Dec 05 2012, Marcus Tomlinson <themarcustomlinson-AT-gmail.com> wrote:

> This library was particularly designed to allow wiring to be done at
> run-time but I will look into compile time-wiring. If I could just
> quickly do some motivation though: Building large computations out of
> smaller ones will not effect performance (in a run-time sense) at all
> due to the way I've designed the multithreading:

I can't imagine a way that multithreading relates to the costs I'm
thinking of. They appear in entirely single-threaded code. The main
question is, "does the CPU need to look at a pointer to discover the
source and/or destination of a flow, or is the relative address already
encoded in the instruction stream?" Auxilliary questions are, "do you
have to waste space for these pointers?" and "can you achieve optimal
locality-of-reference for the storage used in related computations?"

<snip>

> I hope this clarifies my definition of "efficient".

It does, and I agree that these considerations can be important for some
applications, but it seems to me that for smallish component
computations that's going to be really inefficient and you should be
thinking about the issues I cited above.

-- 
Dave Abrahams
BoostPro Computing                  Software Development        Training
http://www.boostpro.com             Clang/LLVM/EDG Compilers  C++  Boost

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