An order-invariant real-to-integer conversion sum

作者：Hallberg Robert^*; Adcroft Alistair

来源：Parallel Computing, 2014, 40(5-6): 140-143.

DOI：10.1016/j.parco.2014.04.007

• Order-invariant
• Global sums
• Parallel programming
• Fixed-point
• Reproducibility

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. Published by Elsevier B.V.

• 出版日期2014-5