QROB benchmarks quantum compilers to reduce overhead on hardware
QROB: Quantifying Realization Overhead in Quantum Compilation via Reverse Construction
Hardware Architecture
Summary
Quantum computers need special software called compilers to turn ideal programs into instructions that fit the actual hardware. The authors created QROB, a method that works backwards from hardware-ready setups to measure how hard it is for compilers to realize programs efficiently. They found that many existing compilers cause much more overhead than necessary, and training software with QROB data can improve performance. Testing on real IBM machines showed that better compilation directly improves the accuracy of quantum runs.
What this means in practice
- •For quantum compiler developers: Use QROB to benchmark and identify inefficiencies in compilers reducing overhead in quantum instruction mapping and scheduling.
- •For quantum hardware operators: Improve quantum program fidelity by applying QROB-based compilation techniques validated on IBM 156-qubit processors.
Authors
Jintao Li, Kaiqi Li, Rui Wang, Yilun Zhao, Kaixuan Huang, Ying Wang, Jialin Zhang, Zheng-An Wang, Xiaoming Sun, Heng Fan
Abstract
Quantum compilation reconciles a program's idealized interaction topology with hardware locality constraints, yet evaluations at scale lack calibrated references for realization overhead. We present QROB, a scalable reverse-construction methodology that generates compilation instances backward from directly realizable configurations, retaining the inverse paths as feasible, compiler-independent references. QROB provides a common evaluation substrate for NISQ SWAP routing and fault-tolerant lattice-surgery scheduling, while extending its reference-preserving principle to capacity-constrained quantum memory-access scheduling. Across systems ranging from 9 to 156 qubits, evaluations highlight QROB's utility as both a diagnostic benchmark and a data source. First, for compiler characterization, QROB reveals substantial realization gaps in existing tools, with NISQ compilers incurring up to 24.1x the reference SWAP cost and fault-tolerant compilers requiring up to 7.0x the reference makespan. Second, as a supervision source for data-driven compilation, a router trained on QROB references outperforms Qiskit SABRE on 84.8% of real-world application circuits. Finally, on real hardware, QROB reference realizations achieve a median mirror-circuit survival rate 1.65x that of full Qiskit O3 compilations across three 156-qubit IBM Heron-r2 processors, demonstrating that closing algorithmic compilation gaps translates directly into physical fidelity gains.