A quantum compiler is one essential and critical component in a quantum computing system to
deploy and optimize the quantum programs onto the underlying physical quantum hardware
platforms. Yet, today’s quantum compilers are still far from optimal. One reason is that most
optimizations in today’s quantum compilers are local program transformations over very few
qubits and gates. In general, it is highly non-trivial for a compiler that runs on a classical
computer to automatically derive large-scale program optimizations at the gate-level.
In this talk, we will discuss how we can systematically enhance the quantum compilers by
introducing high-level program optimizations in the quantum software/compiler infrastructure.
Instead of optimizing the quantum programs at the gate level, we design new quantum

programming language primitives and intermediate representations that can maintain high-
level properties of the programs. These high-level properties can then be leveraged to derive

new large-scale quantum compiler optimizations beyond the capabilities of gate-level
optimizations. In particular, we will introduce optimizing quantum simulation programs over a
Pauli string based intermediate representation, mapping surface code onto superconducting
architectures, and quantum program testing/error mitigation through projection-based
quantum assertions. We believe that the high-level optimization approach can also be
applicable to other quantum application domains and algorithmic properties.