Streaming Reduction Circuit

摘要

Reduction circuits are used to reduce rows of floating point values to single values. Binary floating point operators often have deep pipelines, which may cause hazards when many consecutive rows have to be reduced. We present an algorithm by which any number of consecutive rows of arbitrary lengths can be reduced by a pipelined commutative and associative binary operator in an efficient manner. The algorithm is simple to implement, has a low latency, produces results in-order, and requires only small buffers. Besides, it uses only a single pipeline for the involved operation. The complexity of the algorithm depends on the depth of the pipeline, not on the length of the input rows. In this paper we discuss an implementation of this algorithm and we prove its correctness.