Abstract
This paper describes a technique for obtaining sums of floating point values that are independent of the order-of-operations, and thus attractive for use in global sums in massively parallel computations. The basic idea described here is to convert the floating point values into a representation using a set of long integers, with enough carry-bits to allow these integers to be summed across processors without need of carries at intermediate stages, before conversion of the final sum back to a real number. This approach is being used successfully in an earth system model, in which reproducibility of results is essential.
Original language | English (US) |
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Pages (from-to) | 140-143 |
Number of pages | 4 |
Journal | Parallel Computing |
Volume | 40 |
Issue number | 5-6 |
DOIs | |
State | Published - May 2014 |
All Science Journal Classification (ASJC) codes
- Software
- Theoretical Computer Science
- Hardware and Architecture
- Computer Networks and Communications
- Computer Graphics and Computer-Aided Design
- Artificial Intelligence
Keywords
- Fixed-point
- Global sums
- Order-invariant
- Parallel programming
- Reproducibility