  Compute-mode rendering is becoming more and more attractive for non-standard
rendering applications, due to the high flexibility of compute-mode execution.
These newly designed pipelines often include streaming vertex and geometry
processing stages. In typical triangle meshes, the same transformed vertex is
on average required six times during rendering. To avoid redundant computation,
a post-transform cache is traditionally suggested to enable reuse of vertex
processing results. However, traditional caching neither scales well as the
hardware becomes more parallel, nor can be efficiently implemented in a
software design. We investigate alternative strategies to reusing vertex
shading results on-the-fly for massively parallel software geometry processing.
Forming static and dynamic batching on the data input stream, we analyze the
effectiveness of identifying potential local reuse based on sorting, hashing,
and efficient intra-thread-group communication. Altogether, we present four
vertex reuse strategies, tailored to modern parallel architectures. Our
simulations showcase that our batch-based strategies significantly outperform
parallel caches in terms of reuse. On actual GPU hardware, our evaluation shows
that our strategies not only lead to good reuse of processing results, but also
boost performance by $2-3\times$ compared to na\"ively ignoring reuse in a
variety of practical applications.
