isQ: An Integrated Software Stack for Quantum Programming

We introduce isQ, a new software stack for quantum programming in an imperative programming language, also named isQ. The aim of isQ is to make programmers write quantum programs as conveniently as possible. In particular, 1) the isQ language and its compiler contain many useful features, including but not limited to classical control flow, such as recursion, decomposition of self-defined unitary gates, and oracle programming and its circuit realization. 2) To make it flexible, an isQ program can be compiled into several different kinds of intermediate representation and assemblies, including QIR, eQASM, OpenQASM 3.0, and QCIS (specially tailored for the superconducting quantum hardware at the University of Science and Technology of China). 3) Besides interfacing isQ with real superconducting hardware, a QIR simulator is also developed for the demonstration and testing of isQ programs. The isQ software stack encompasses abundant compiler optimizations of high-level quantum programs. To realize it, a distinct multilevel intermediate representation (MLIR) dialect name isQ-IR is proposed.