The IBM Q architecture provides the following physical gates (primitives).
|QASM||Name||Qubit Count||Parameter Count|
Reset is a separate instruction, but can theoretically be implemented as
measure q b;
if (b == 1) x q;
where x is U(PI,0,PI) and PI is a half rotation (π).
The universal single-qubit instruction takes 3 parameters. Here the question is the theoretical precision (value space) of these parameters and the physical precision (tolerance) of their implementation in hardware.