Get a compressed tree representation of the reference sample by using stim::ReferenceSampleTree::from_circuit_reference_sample(circuit).
The reason for a tree, instead of raw run length encoding, is to support nested loops (e.g. physical surface code rounds repeating within repeated logical operations).
Example test:
CircuitGenParameters params(10000, 3, "rotated_memory_x");
auto circuit = generate_surface_code_circuit(params).circuit;
circuit.blocks[0].append_from_text("X 10 11 12 13");
auto ref = ReferenceSampleTree::from_circuit_reference_sample(circuit);
ASSERT_EQ(ref.str(), "1*(''+2*('00000000')+4999*('0110000000110000')+1*('000000000'))");
Example benchmark (25 milliseconds to do a distance 31 surface code with a billion rounds):
CircuitGenParameters params(1000000000, 31, "rotated_memory_x");
auto circuit = generate_surface_code_circuit(params).circuit;
simd_bits<MAX_BITWORD_WIDTH> ref(0);
auto total = 0;
benchmark_go([&]() {
auto result = ReferenceSampleTree::from_circuit_reference_sample(circuit);
total += result.empty();
})
.goal_millis(25);
Get a compressed tree representation of the reference sample by using
stim::ReferenceSampleTree::from_circuit_reference_sample(circuit).The reason for a tree, instead of raw run length encoding, is to support nested loops (e.g. physical surface code rounds repeating within repeated logical operations).
Example test:
Example benchmark (25 milliseconds to do a distance 31 surface code with a billion rounds):
Part of https://github.com/quantumlib/Stim/issues/768