Investigating Retargetability Claims for Quantum Compilers

TL;DR

This paper evaluates the retargetability of quantum compilers across different hardware platforms, introducing a metric and analyzing Tket, Qiskit, and ProjectQ to guide developers in choosing suitable tools.

Contribution

It develops a new metric for assessing quantum compiler retargetability and provides an empirical comparison of three leading compilers.

Findings

Tket shows the highest retargetability among the tested compilers.

Qiskit has moderate retargetability, close to Tket.

ProjectQ exhibits the lowest retargetability.

Abstract

In the NISQ-era, there is a wide variety of hardware manufacturers building quantum computers. Each of these companies may choose different approaches and hardware architectures for their machines. This poses a problem for quantum software engineering, as the retargetability of quantum programs across different hardware platforms becomes a non-trivial challenge. In response to this problem, various retargetable quantum compilers have been presented in the scientific literature. These promise the ability to compile software for different hardware platforms, enabling retargetability for quantum software. In this paper, we develop and apply a metric by which the retargetability of the quantum compilers can be assessed. We develop and run a study to analyze key aspects regarding the retargetability of the compilers Tket, Qiskit, and ProjectQ. Our findings indicate that Tket demonstrates the highest level of retargetability, closely followed by Qiskit, while ProjectQ lags behind. These results provide insights for quantum software developers in selecting appropriate compilers for their use-cases, and highlight areas for improvement in quantum compilers.