  We demonstrate the utility of the Multi-Level Intermediate Representation
(MLIR) for quantum computing. Specifically, we extend MLIR with a new quantum
dialect that enables the expression and compilation of common quantum assembly
languages. The true utility of this dialect is in its ability to be lowered to
the LLVM intermediate representation (IR) in a manner that is adherent to the
quantum intermediate representation (QIR) specification recently proposed by
Microsoft. We leverage a qcor-enabled implementation of the QIR quantum runtime
API to enable a retargetable (quantum hardware agnostic) compiler workflow
mapping quantum languages to hybrid quantum-classical binary executables and
object code. We evaluate and demonstrate this novel compiler workflow with
quantum programs written in OpenQASM 2.0. We provide concrete examples
detailing the generation of MLIR from OpenQASM source files, the lowering
process from MLIR to LLVM IR, and ultimately the generation of executable
binaries targeting available quantum processors.
