Library structure

This page provides an overview of the staq library and the overall directory structure.

Repository

Directory	Description
include	The main source code directory
libs	External libraries
qasm	Example openQASM source files
qasmtools	Library which defines QASM syntax trees and a parser
qpus	Example device representation files
staq	The main staq compiler
tools	Holds the staq tool suite
unit_tests	Unit testing via Google Test/Mock (source included)

Source

Directory	Description
include/gates	Holds representations & tools for working with particular gate sets
.../channel.hpp	Tools for working with Clifford gates in the channel representation -- that is, Clifford gates represented as permutations of the Pauli group and arbitrary Pauli-axis rotations as sums of Paulis
include/mapping	Classes & algorithms for mapping to physical/constrained hardware
include/optimization	Optimizations on QASM ASTs
.../rotation_folding.hpp	An optimization to merge or cancel non-Clifford rotation gates (e.g., t, tdg, rx, ...) when possible
.../simplify.hpp	A basic adjacent gate cancellation optimization
include/output	Transpilers from QASM into other languages
include/synthesis	Algorithms for synthesizing various types of circuits
.../linear_reversible.hpp	Contains algorithms for synthesizing CX circuits from permutation matrices, either unconstrained (Gaussian elimination) and constrained by physical architectures (Steiner tree based)
.../cnot_dihedral.hpp	Contains algorithms for synthesizing CX+rz circuits from their Fourier expansions. Implements both unconstrained and topologically constrained versions
.../logic_synthesis.hpp	Implements synthesis of quantum circuits from classical Verilog files. Uses the EPFL tools & implementation of LUT-based Hierarchical Reversible Logic Synthesis
include/tools	Contains miscellaneous tools for working with QASM ASTs
.../resource_estimator.hpp	Computes the gate/depth/qubit counts of a circuit
include/transformations	Utility AST transformations
.../desugar.hpp	Transformation to expand all gates applied to registers
.../inline.hpp	Configurable AST inliner. Can be used to inline only certain gates
.../oracle_synthesizer.hpp	Replaces oracle declarations with synthesized circuits
.../substitution.hpp	Generic substitution routines. Includes simple variable substitution, as well as a powerful register substitution framework

Mapping

Directory	Description
include/mapping/device.hpp	Defines the physical device class, as well as some example devices
include/mapping/layout	Algorithms and tools for generating an initial layout of a circuit onto a device
.../basic.hpp	Assigns physical qubits in order to logical qubits
.../bestfit.hpp	Assigns physical qubits so that the highest fidelity couplings are mapped to the logical qubits with the most CX gates
.../eager.hpp	Assigns physical qubits on a 'by-need' basis -- that is, assigns a valid physically coupled pair of qubits whenever an unmapped CX gate is found
include/mapping/mapping	Algorithms and tools for mapping CX between uncoupled qubits
.../swap.hpp	Swaps qubits along a shortest path from the CX control to target
.../steiner.hpp	Re-synthesizes the circuit using a physically constrained version of Gray-synth

Included libs

Directory	Description
CLI	Parsing command line options. EPFL dependency
caterpillar	EPFL library for quantum circuit synthesis
easy	EPFL library for ESOP manipulation
ez	EPFL dependency
fmt	Output formatting. EPFL dependency
glucose	SAT solver. EPFL dependency
kitty	EPFL truth table library
lorina	EPFL library for parsing of classical logic formats
mockturtle	EPFL library for logic network representation
nlohmann	JSON library for C++
pthreadwin32	Windows pthread compatibility. Glucose dependency.
rang	Terminal colours. EPFL dependency
sparsepp	Hash map library. EPFL dependency
tweedledum	EPFL library for general purpose quantum compilation
zlib	Windows zlib compatibility. Glucose dependency.