  Quantum computers are traditionally operated by programmers at the
granularity of a gate-based instruction set. However, the actual device-level
control of a quantum computer is performed via analog pulses. We introduce a
compiler that exploits direct control at this microarchitectural level to
achieve significant improvements for quantum programs. Unlike quantum optimal
control, our approach is bootstrapped from existing gate calibrations and the
resulting pulses are simple. Our techniques are applicable to any quantum
computer and realizable on current devices. We validate our techniques with
millions of experimental shots on IBM quantum computers, controlled via the
OpenPulse control interface. For representative benchmarks, our pulse control
techniques achieve both 1.6x lower error rates and 2x faster execution time,
relative to standard gate-based compilation. These improvements are critical in
the near-term era of quantum computing, which is bottlenecked by error rates
and qubit lifetimes.
