  Quantum resource theories are a powerful framework to characterize and
quantify relevant quantum phenomena and identify processes that optimize their
use for different tasks. Here, we define a resource measure for magic, the
sought-after property in most fault-tolerant quantum computers. In contrast to
previous literature, our formulation is based on bosonic codes, well-studied
tools in continuous-variable quantum computation. Particularly, we use the
Gottesman-Kitaev-Preskill code to represent multi-qubit states and consider the
resource theory for the Wigner negativity. Our techniques are useful to find
resource lower bounds for different applications as state conversion and
general unitary synthesis, in which measurements, auxiliary states, and
classical feed-forward are allowed. The analytical expression of our magic
measure allows us to extend current analysis limited to small dimensions,
easily addressing systems of up to 12 qubits.
