(j3.2006) (SC22WG5.5365) Nondeterminacy of reductions

[Bill Long]

On Nov 11, 2014, at 1:29 PM, Van Snyder <Van.Snyder at jpl.nasa.gov> wrote:

> Sylvain Collange et al remark in
> 
> "Full-Speed Deterministic Bit-Accurate Parallel Floating-Point Summation
> on Multi- and Many-Core Architectures?


For some very misleading interpretation of ?Full-speed?.  

Cheers,
Bill



> 
> https://www.researchgate.net/publication/267982095_Full-Speed_Deterministic_Bit-Accurate_Parallel_Floating-Point_Summation_on_Multi-_and_Many-Core_Architectures
> 
> that parallel computations, especially reductions, are non-deterministic
> due to floating-point computations not being computationally
> associative.

Bill Long                                                                       longb at cray.com
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