QIRO: A Static Single Assignment-based Quantum Program Representation for Optimization

Abstract

We propose an IR for quantum computing that directly exposes quantum and classical data dependencies for the purpose of optimization. The Quantum Intermediate Representation for Optimization (QIRO) consists of two dialects, one input dialect and one that is specifically tailored to enable quantum-classical co-optimization. While the first employs a perhaps more intuitive memory-semantics (quantum operations act on qubits via side-effects), the latter uses value-semantics (operations consume and produce states) to integrate quantum dataflow in the IR’s Static Single Assignment (SSA) graph. Crucially, this allows for a host of optimizations that leverage dataflow analysis. We discuss how to map existing quantum programming languages to the input dialect and how to lower the resulting IR to the optimization dialect. We present a prototype implementation based on MLIR that includes several quantum-specific optimization passes. Our benchmarks show that significant improvements in resource requirements are possible even through static optimization. In contrast to circuit optimization at run time, this is achieved while incurring only a small constant overhead in compilation time, making this a compelling approach for quantum program optimization at application scale.

Programming Quantum Neural Networks on NISQ Systems: An Overview of Technologies and Methodologies

“…Following the existing development of machine learning frameworks, such as , it is likely that in the future, QNN frameworks will rely more and more on domain-specific languages and compiler technologies to provide an Intermediate Representation (IR) that can be translated to different quantum hardware (and simulator) backends. Compiler toolchains, such as and [ 114 , 115 , 116 ], are already in use by the Intel Quantum SDK [ 98 ], and . These technologies might have a prominent role in the future of programming QNN on a quantum computer.…”

QFaaS: A Serverless Function-as-a-Service Framework for Quantum Computing

“…Besides, there are numerous quantum languages and SDKs proposed by research groups and other companies over the world, such as Forest and pyQuil by Rigetti [47]; Strawberry Fields [37] and PennyLane [4] by Xanadu; Quingo [18]; QIRO [34]; or qcor [42].…”