Precise Pointer Analysis in High-Level Synthesis

Abstract

Pointer analysis computes the set of memory locations that each pointer access can point to during hardware runtime. The more sensitive the pointer analysis, the more precise these sets are likely to be, reducing unnecessary sharing of memory resources between instructions during high-level synthesis (HLS) memory generation. Despite the importance of precision, modern HLS tools typically sacrifice precision to prioritise quicker analysis times, although there are several pointer analyses that can produce reasonably precise pointsto sets within an acceptable amount of time. In this paper, we explore the effects of precise pointer analysis within a modern HLS tool (LegUp) on a set of benchmark programs (PTABen) that are challenging to its original pointer analysis. We see precise analysis that reduces unnecessary memory sharing, leading to average LUT savings of 60% and runtime improvements of 42%.

A Case for Precise, Fine-Grained Pointer Synthesis in High-Level Synthesis

“…Comparison to our prior work. This article extends our conference paper at FPL 2020 [31] in three ways. Firstly, in our conference paper, we identified that the points-to graph supplied to HLS pointer synthesis is often imprecise.…”