Weaver: A Retargetable Compiler Framework for FPQA Quantum Architectures

Abstract: While the prominent quantum computing architectures are based on superconducting technology, new quantum hardware technologies are emerging, such as Trapped Ions, Neutral Atoms (or FPQAs), Silicon Spin Qubits, etc. This diverse set of technologies presents fundamental trade-offs in terms of scalability, performance, manufacturing, and operating expenses. To manage these diverse quantum technologies, there is a growing need for a retargetable compiler that can efficiently adapt existing code to these emerging hardware platforms. Such a retargetable compiler must be extensible to support new and rapidly evolving technologies, performant with fast compilation times and high-fidelity execution, and verifiable through rigorous equivalence checking to ensure the functional equivalence of the retargeted code. To this end, we present $Weaver$, the first extensible, performant, and verifiable retargetable quantum compiler framework with a focus on FPQAs due to their unique, promising features. $Weaver$ introduces WQASM, the first formal extension of the standard OpenQASM quantum assembly with FPQA-specific instructions to support their distinct capabilities. Next, $Weaver$ implements the WOptimizer, an extensible set of FPQA-specific optimization passes to improve execution quality. Last, the WChecker automatically checks for equivalence between the original and the retargeted code. Our evaluation shows that $Weaver$ improves compilation times by $10^3\times$, execution times by $4.4\times$, and execution fidelity by $10\%$, on average, compared to superconducting and state-of-the-art (non-retargetable) FPQA compilers.