Realizing quantum computing algorithms often requires instantiating and using ancilla qubits. These spare qubits are used only temporarily in the quantum circuit and thus are often utilized with encode-compute-decode operations. In particular, many recently developed high-level quantum programming languages heavily utilize ancilla qubits to maintain internal states with similar gate sequences to implement various programming constructs. We present SPARE a quantum circuit optimizer that breaks down and restructures these encode-compute-decode patterns and uses ancilla qubit state information for circuit optimization. SPARE achieves up to 2.2× improvement in circuit depth gates against the Spire and up to 10.6× improvement in circuit depth against the Unqomp compilers for Tower and Silq high-level languages, respectively. SPARE also achieves up to 1.68× lower circuit depth compared to gate-level rewriting tools like Quartz with an exponentially faster runtime, bridging the gap between gate-level optimizers and quantum-language compilers.