Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

support cu1 fusion #334

Merged
merged 2 commits into from
Sep 6, 2019
+27 −15
Merged

support cu1 fusion #334

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
e89a3bc
support cu1 fusion
hhorii Aug 31, 2019
f3c075e
simplify a logic to identify an unrolled cu1
hhorii Sep 6, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
42 changes: 27 additions & 15 deletions src/transpile/fusion.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -71,9 +71,9 @@ class Fusion : public CircuitOptimization {
const reg_t& dst_sorted_qubits,
const cmatrix_t& mat) const;

bool only_u1(const oplist_t& ops,
const uint_t from,
const uint_t until) const;
bool is_diagonal(const oplist_t& ops,
const uint_t from,
const uint_t until) const;

double estimate_cost(const oplist_t& ops,
const uint_t from,
Expand Down Expand Up @@ -116,6 +116,7 @@ const std::vector<std::string> Fusion::supported_gates({
// Two-qubit gates
"CX", // Controlled-X gate (CNOT)
"cx", // Controlled-X gate (CNOT)
"cu1", // Controlled-U1 gate
"cz", // Controlled-Z gate
"swap" // SWAP gate
// Three-qubit gates
Expand Down Expand Up @@ -509,26 +510,30 @@ cmatrix_t Fusion::sort_matrix(const reg_t &src,
return ret;
}

bool Fusion::only_u1(const std::vector<op_t>& ops,
const uint_t from,
const uint_t until) const {
bool Fusion::is_diagonal(const std::vector<op_t>& ops,
const uint_t from,
const uint_t until) const {

// check unitary matrix of ops between "from" and "to" is a diagonal matrix

for (uint_t i = from; i <= until; ++i) {
if (ops[i].name == "u1")
continue;
if (from < i && (i + 2) <= until
&& ops[i - 1].name == "u1"
&& ops[i ].name == "cx"
// ┌───┐┌────┐┌───┐
// ─┤ X ├┤ U1 ├┤ X ├
// └─┬─┘└────┘└─┬─┘
// ───■──────────■─-
if ((i + 2) <= until
&& ops[i + 0].name == "cx"
&& ops[i + 1].name == "u1"
&& ops[i + 2].name == "cx"
&& ops[i - 1].qubits[0] == ops[i ].qubits[1]
&& ops[i ].qubits[1] == ops[i + 1].qubits[0]
&& ops[i + 0].qubits[1] == ops[i + 1].qubits[0]
&& ops[i + 1].qubits[0] == ops[i + 2].qubits[1]
&& ops[i ].qubits[0] == ops[i + 2].qubits[0] )
&& ops[i + 0].qubits[0] == ops[i + 2].qubits[0] )
{
i += 2;
continue;
}
if (ops[i].name == "u1" || ops[i].name == "cu1")
continue;
return false;
}
return true;
Expand All @@ -537,7 +542,7 @@ bool Fusion::only_u1(const std::vector<op_t>& ops,
double Fusion::estimate_cost(const std::vector<op_t>& ops,
const uint_t from,
const uint_t until) const {
if (only_u1(ops, from, until))
if (is_diagonal(ops, from, until))
return cost_factor_;

reg_t fusion_qubits;
Expand Down Expand Up @@ -579,6 +584,13 @@ cmatrix_t Fusion::matrix(const op_t& op) const {
{ {1, 0}, {0, 0} },
{ {0, 0}, std::exp( complex_t(0, 1.) * std::real(op.params[0])) }}
);
} else if (op.name == "cu1") { // zero-X90 pulse waltz gate
return Utils::make_matrix<complex_t>( {
{ {1, 0}, {0, 0}, {0, 0}, {0, 0} },
{ {0, 0}, {1, 0}, {0, 0}, {0, 0} },
{ {0, 0}, {0, 0}, {1, 0}, {0, 0} },
{ {0, 0}, {0, 0}, {0, 0}, std::exp( complex_t(0, 1.) * std::real(op.params[0])) }}
);
} else if (op.name == "u2") { // single-X90 pulse waltz gate
return Utils::Matrix::u3( M_PI / 2., std::real(op.params[0]), std::real(op.params[1]));
} else if (op.name == "u3" || op.name == "U") { // two X90 pulse waltz gate
Expand Down