Puncalc: Task-Based Parallelism and Speculative Reevaluation in Spreadsheets

Spreadsheets are commonly declarative, first-order functional programs and are used as organizational tools, for end-user development, and for educational purposes. Spreadsheet end-users are usually domain experts who use spreadsheets as their main computational model, but are seldom trained IT professionals who can leverage today's abundant multicore processors for spreadsheet computation. In this paper, we present an algorithm for automatic, parallel evaluation of spreadsheets targeting shared-memory multicore architectures, that lets end-users transparently make use of their multicore processors. We evaluate our algorithm on a set of synthetic and real-world spreadsheets, and obtain up to 16 times speedup.