Techniques are disclosed for reducing or eliminating loop overhead caused by function calls in processors that form part of a pipeline architecture. The processors in the pipeline process data blocks in an iterative fashion, with each processor in the pipeline completing one of several iterations associated with a processing loop for a commonly-executed function. The described techniques leverage the use of message passing for pipelined processors to enable an upstream processor to signal to a downstream processor when processing has been completed, and thus a data block is ready for further processing in accordance with the next loop processing iteration. The described techniques facilitate a zero loop overhead architecture, enable continuous data block processing, and allow the processing pipeline to function indefinitely within the main body of the processing loop associated with the commonly-executed function where efficiency is greatest.