Allow AutoRebase to ISWAPMax

pytket/binders/circuit_library.cpp

@@ -68,6 +68,14 @@ PYBIND11_MODULE(circuit_library, library_m) {
   library_m.def(
       "CX_using_ZZMax", &CircPool::CX_using_ZZMax,
       "Equivalent to CX, using only ZZMax, Rx and Rz gates");
+  library_m.def(
+      "CX_using_ISWAPMax", &CircPool::CX_using_ISWAPMax,
+      "Equivalent to CX, using only ISWAPMax and single-qubit gates");
+  library_m.def(
+      "CX_using_ISWAPMax_and_swap", &CircPool::CX_using_ISWAPMax_and_swap,
+      "Equivalent to CX, using only ISWAPMax and single-qubit gates, up to a "
+      "wire swap that is encoded in the implicit qubit permutation of the "
+      "Circuit");
   library_m.def(
       "CX_using_ZZPhase", &CircPool::CX_using_ZZPhase,
       "Equivalent to CX, using only ZZPhase, Rx and Rz gates");
@@ -213,6 +221,12 @@ PYBIND11_MODULE(circuit_library, library_m) {
   library_m.def(
       "ISWAP_using_CX", &CircPool::ISWAP_using_CX,
       "Equivalent to ISWAP, using CX, U3 and Rz gates");
+  library_m.def(
+      "ISWAPMax_using_TK2", &CircPool::ISWAPMax_using_TK2,
+      "Equivalent to ISWAPMax, using a TK2 gate");
+  library_m.def(
+      "ISWAPMax_using_CX", &CircPool::ISWAPMax_using_CX,
+      "Equivalent to ISWAPMax, using CX, U3 and Rz gates");
   library_m.def(
       "XXPhase_using_TK2", &CircPool::XXPhase_using_TK2,
       "Equivalent to XXPhase, using a TK2 gate");
@@ -261,6 +275,14 @@ PYBIND11_MODULE(circuit_library, library_m) {
       "TK2_using_ZZMax_and_swap", &CircPool::TK2_using_ZZMax_and_swap,
       "Equivalent to TK2, up to a wire swap that is encoded in the implicit "
       "qubit permutation of the Circuit, using up to 3 ZZMax gates.");
+  library_m.def(
+      "TK2_using_ISWAPMax", &CircPool::TK2_using_ISWAPMax,
+      "Equivalent to TK2, using only ISWAPMax and single-qubit gates.");
+  library_m.def(
+      "TK2_using_ISWAPMax_and_swap", &CircPool::TK2_using_ISWAPMax_and_swap,
+      "Equivalent to TK2, using only ISWAPMax and single-qubit gates, up to a "
+      "wire swap that is encoded in the implicit qubit permutation of the "
+      "Circuit.");
   library_m.def(
       "XXPhase3_using_TK2", &CircPool::XXPhase3_using_TK2,
       "Equivalent to XXPhase3, using three TK2 gates");

pytket/conanfile.py

@@ -38,7 +38,7 @@ def requirements(self):
         self.requires("pybind11_json/tci-0.2.15@tket/stable")
         self.requires("symengine/tci-0.14.0@tket/stable")
         self.requires("tkassert/0.3.4@tket/stable")
-        self.requires("tket/2.1.1@tket/stable")
+        self.requires("tket/2.1.2@tket/stable")
         self.requires("tklog/0.3.3@tket/stable")
         self.requires("tkrng/0.3.3@tket/stable")
         self.requires("tktokenswap/0.3.11@tket/stable")

pytket/docs/changelog.rst

@@ -1,6 +1,12 @@
 Changelog
 =========
 
+Unreleased
+----------
+
+* Add methods in `circuit_library` to convert `CX` and `TK2` to and from
+  `ISWAPMax`, and support for `AutoRebase` targeting `ISWAPMax`.
+
 2.1.0 (March 2025)
 ------------------
 

pytket/pytket/_tket/circuit_library.pyi

@@ -2,7 +2,7 @@ from __future__ import annotations
 import pytket._tket.circuit
 import sympy
 import typing
-__all__ = ['BRIDGE', 'BRIDGE_using_CX_0', 'BRIDGE_using_CX_1', 'C3X_normal_decomp', 'C4X_normal_decomp', 'CCX', 'CCX_modulo_phase_shift', 'CCX_normal_decomp', 'CH_using_CX', 'CRx_using_CX', 'CRx_using_TK2', 'CRy_using_CX', 'CRy_using_TK2', 'CRz_using_CX', 'CRz_using_TK2', 'CSWAP_using_CX', 'CSX_using_CX', 'CSXdg_using_CX', 'CS_using_CX', 'CSdg_using_CX', 'CU1_using_CX', 'CU1_using_TK2', 'CU3_using_CX', 'CV_using_CX', 'CVdg_using_CX', 'CX', 'CX_S_CX_reduced', 'CX_S_V_XC_reduced', 'CX_VS_CX_reduced', 'CX_V_CX_reduced', 'CX_V_S_XC_reduced', 'CX_XC_reduced', 'CX_using_AAMS', 'CX_using_ECR', 'CX_using_TK2', 'CX_using_XXPhase_0', 'CX_using_XXPhase_1', 'CX_using_ZZMax', 'CX_using_ZZPhase', 'CX_using_flipped_CX', 'CY_using_CX', 'CZ_using_CX', 'CnX_vchain_decomp', 'ECR_using_CX', 'ESWAP_using_CX', 'ESWAP_using_TK2', 'FSim_using_CX', 'FSim_using_TK2', 'H_CZ_H', 'ISWAP_using_CX', 'ISWAP_using_TK2', 'NPhasedX_using_PhasedX', 'PhasedISWAP_using_CX', 'PhasedISWAP_using_TK2', 'Rx_using_GPI', 'Ry_using_GPI', 'Rz_using_GPI', 'SWAP_using_CX_0', 'SWAP_using_CX_1', 'TK1_to_PhasedXRz', 'TK1_to_RxRy', 'TK1_to_RzH', 'TK1_to_RzRx', 'TK1_to_RzSX', 'TK1_to_RzXSX', 'TK1_to_TK1', 'TK1_to_U3', 'TK1_using_GPI', 'TK2_using_3xCX', 'TK2_using_AAMS', 'TK2_using_CX', 'TK2_using_CX_and_swap', 'TK2_using_TK2', 'TK2_using_TK2_or_swap', 'TK2_using_ZZMax', 'TK2_using_ZZMax_and_swap', 'TK2_using_ZZPhase', 'TK2_using_ZZPhase_and_swap', 'TK2_using_normalised_TK2', 'X', 'X1_CX', 'XXPhase3_using_CX', 'XXPhase3_using_TK2', 'XXPhase_using_AAMS', 'XXPhase_using_CX', 'XXPhase_using_TK2', 'YYPhase_using_AAMS', 'YYPhase_using_CX', 'YYPhase_using_TK2', 'Z0_CX', 'ZZMax_using_CX', 'ZZPhase_using_AAMS', 'ZZPhase_using_CX', 'ZZPhase_using_TK2', 'approx_TK2_using_1xCX', 'approx_TK2_using_1xZZPhase', 'approx_TK2_using_2xCX', 'approx_TK2_using_2xZZPhase', 'ladder_down', 'ladder_down_2', 'ladder_up']
+__all__ = ['BRIDGE', 'BRIDGE_using_CX_0', 'BRIDGE_using_CX_1', 'C3X_normal_decomp', 'C4X_normal_decomp', 'CCX', 'CCX_modulo_phase_shift', 'CCX_normal_decomp', 'CH_using_CX', 'CRx_using_CX', 'CRx_using_TK2', 'CRy_using_CX', 'CRy_using_TK2', 'CRz_using_CX', 'CRz_using_TK2', 'CSWAP_using_CX', 'CSX_using_CX', 'CSXdg_using_CX', 'CS_using_CX', 'CSdg_using_CX', 'CU1_using_CX', 'CU1_using_TK2', 'CU3_using_CX', 'CV_using_CX', 'CVdg_using_CX', 'CX', 'CX_S_CX_reduced', 'CX_S_V_XC_reduced', 'CX_VS_CX_reduced', 'CX_V_CX_reduced', 'CX_V_S_XC_reduced', 'CX_XC_reduced', 'CX_using_AAMS', 'CX_using_ECR', 'CX_using_ISWAPMax', 'CX_using_ISWAPMax_and_swap', 'CX_using_TK2', 'CX_using_XXPhase_0', 'CX_using_XXPhase_1', 'CX_using_ZZMax', 'CX_using_ZZPhase', 'CX_using_flipped_CX', 'CY_using_CX', 'CZ_using_CX', 'CnX_vchain_decomp', 'ECR_using_CX', 'ESWAP_using_CX', 'ESWAP_using_TK2', 'FSim_using_CX', 'FSim_using_TK2', 'H_CZ_H', 'ISWAPMax_using_CX', 'ISWAPMax_using_TK2', 'ISWAP_using_CX', 'ISWAP_using_TK2', 'NPhasedX_using_PhasedX', 'PhasedISWAP_using_CX', 'PhasedISWAP_using_TK2', 'Rx_using_GPI', 'Ry_using_GPI', 'Rz_using_GPI', 'SWAP_using_CX_0', 'SWAP_using_CX_1', 'TK1_to_PhasedXRz', 'TK1_to_RxRy', 'TK1_to_RzH', 'TK1_to_RzRx', 'TK1_to_RzSX', 'TK1_to_RzXSX', 'TK1_to_TK1', 'TK1_to_U3', 'TK1_using_GPI', 'TK2_using_3xCX', 'TK2_using_AAMS', 'TK2_using_CX', 'TK2_using_CX_and_swap', 'TK2_using_ISWAPMax', 'TK2_using_ISWAPMax_and_swap', 'TK2_using_TK2', 'TK2_using_TK2_or_swap', 'TK2_using_ZZMax', 'TK2_using_ZZMax_and_swap', 'TK2_using_ZZPhase', 'TK2_using_ZZPhase_and_swap', 'TK2_using_normalised_TK2', 'X', 'X1_CX', 'XXPhase3_using_CX', 'XXPhase3_using_TK2', 'XXPhase_using_AAMS', 'XXPhase_using_CX', 'XXPhase_using_TK2', 'YYPhase_using_AAMS', 'YYPhase_using_CX', 'YYPhase_using_TK2', 'Z0_CX', 'ZZMax_using_CX', 'ZZPhase_using_AAMS', 'ZZPhase_using_CX', 'ZZPhase_using_TK2', 'approx_TK2_using_1xCX', 'approx_TK2_using_1xZZPhase', 'approx_TK2_using_2xCX', 'approx_TK2_using_2xZZPhase', 'ladder_down', 'ladder_down_2', 'ladder_up']
 def BRIDGE() -> pytket._tket.circuit.Circuit:
     """
     Just a BRIDGE[0,1,2] gate
@@ -139,6 +139,14 @@ def CX_using_ECR() -> pytket._tket.circuit.Circuit:
     """
     Equivalent to CX, using only ECR, Rx and U3 gates
     """
+def CX_using_ISWAPMax() -> pytket._tket.circuit.Circuit:
+    """
+    Equivalent to CX, using only ISWAPMax and single-qubit gates
+    """
+def CX_using_ISWAPMax_and_swap() -> pytket._tket.circuit.Circuit:
+    """
+    Equivalent to CX, using only ISWAPMax and single-qubit gates, up to a wire swap that is encoded in the implicit qubit permutation of the Circuit
+    """
 def CX_using_TK2() -> pytket._tket.circuit.Circuit:
     """
     Equivalent to CX, using a TK2 and single-qubit gates
@@ -204,6 +212,14 @@ def H_CZ_H() -> pytket._tket.circuit.Circuit:
     """
     H[1]; CZ[0,1]; H[1] 
     """
+def ISWAPMax_using_CX() -> pytket._tket.circuit.Circuit:
+    """
+    Equivalent to ISWAPMax, using CX, U3 and Rz gates
+    """
+def ISWAPMax_using_TK2() -> pytket._tket.circuit.Circuit:
+    """
+    Equivalent to ISWAPMax, using a TK2 gate
+    """
 def ISWAP_using_CX(arg0: sympy.Expr | float) -> pytket._tket.circuit.Circuit:
     """
     Equivalent to ISWAP, using CX, U3 and Rz gates
@@ -302,6 +318,14 @@ def TK2_using_CX_and_swap(arg0: sympy.Expr | float, arg1: sympy.Expr | float, ar
 
     The decomposition minimizes the number of CX gates.
     """
+def TK2_using_ISWAPMax(arg0: sympy.Expr | float, arg1: sympy.Expr | float, arg2: sympy.Expr | float) -> pytket._tket.circuit.Circuit:
+    """
+    Equivalent to TK2, using only ISWAPMax and single-qubit gates.
+    """
+def TK2_using_ISWAPMax_and_swap(arg0: sympy.Expr | float, arg1: sympy.Expr | float, arg2: sympy.Expr | float) -> pytket._tket.circuit.Circuit:
+    """
+    Equivalent to TK2, using only ISWAPMax and single-qubit gates, up to a wire swap that is encoded in the implicit qubit permutation of the Circuit.
+    """
 def TK2_using_TK2(arg0: sympy.Expr | float, arg1: sympy.Expr | float, arg2: sympy.Expr | float) -> pytket._tket.circuit.Circuit:
     """
     A circuit of a single TK2 gate with given parameters

pytket/pytket/circuit_library/__init__.py

@@ -48,6 +48,8 @@
     CX_using_AAMS,
     CX_using_ECR,
     CX_using_flipped_CX,
+    CX_using_ISWAPMax,
+    CX_using_ISWAPMax_and_swap,
     CX_using_TK2,
     CX_using_XXPhase_0,
     CX_using_XXPhase_1,
@@ -66,6 +68,8 @@
     FSim_using_TK2,
     ISWAP_using_CX,
     ISWAP_using_TK2,
+    ISWAPMax_using_CX,
+    ISWAPMax_using_TK2,
     NPhasedX_using_PhasedX,
     PhasedISWAP_using_CX,
     PhasedISWAP_using_TK2,
@@ -84,6 +88,8 @@
     TK2_using_AAMS,
     TK2_using_CX,
     TK2_using_CX_and_swap,
+    TK2_using_ISWAPMax,
+    TK2_using_ISWAPMax_and_swap,
     TK2_using_normalised_TK2,
     TK2_using_TK2_or_swap,
     TK2_using_ZZMax,

pytket/tests/predicates_test.py

@@ -859,6 +859,12 @@ def test_rz_sx_decomp() -> None:
     assert c == comp
 
 
+def test_iswapmax_autorebase() -> None:
+    c = Circuit(2).H(0).CX(0, 1)
+    assert AutoRebase({OpType.ISWAPMax, OpType.TK1}).apply(c)
+    assert c.n_gates_of_type(OpType.ISWAPMax) <= 2
+
+
 def test_flatten_relabel_pass() -> None:
     c = Circuit(3)
     c.H(1).H(2)

tket/conanfile.py

@@ -23,7 +23,7 @@
 
 class TketConan(ConanFile):
     name = "tket"
-    version = "2.1.1"
+    version = "2.1.2"
     package_type = "library"
     license = "Apache 2"
     homepage = "https://github.com/CQCL/tket"

tket/include/tket/Circuit/CircPool.hpp

@@ -40,6 +40,14 @@ const Circuit &CX_using_ECR();
 /** Equivalent to CX, using only ZZMax, Rx and Rz gates */
 const Circuit &CX_using_ZZMax();
 
+/** Equivalent to CX, using only ISWAPMax and single-qubit gates */
+const Circuit &CX_using_ISWAPMax();
+
+/** Equivalent to CX, using only ISWAPMax and single-qubit gates, with an
+ *  implicit swap.
+ */
+const Circuit &CX_using_ISWAPMax_and_swap();
+
 /** Equivalent to CX, using only ZZPhase, Rx and Rz gates */
 const Circuit &CX_using_ZZPhase();
 
@@ -196,6 +204,12 @@ const Circuit &ECR_using_CX();
 /** Equivalent to ZZMax, using CX, Rz and U3 gates */
 const Circuit &ZZMax_using_CX();
 
+/** Equivalent to ISWAPMax, using a TK2 gate **/
+const Circuit &ISWAPMax_using_TK2();
+
+/** Equivalent to ISWAPMax, using CX, Rz and U3 gates **/
+const Circuit &ISWAPMax_using_CX();
+
 /** Equivalent to CRz, using a TK2 and TK1 gates */
 Circuit CRz_using_TK2(const Expr &alpha);
 
@@ -424,6 +438,16 @@ Circuit TK2_using_ZZMax(const Expr &alpha, const Expr &beta, const Expr &gamma);
 Circuit TK2_using_ZZMax_and_swap(
     const Expr &alpha, const Expr &beta, const Expr &gamma);
 
+/** Equivalent to TK2, using only ISWAPMax and single-qubit gates */
+Circuit TK2_using_ISWAPMax(
+    const Expr &alpha, const Expr &beta, const Expr &gamma);
+
+/** Equivalent to TK2, using only ISWAPMax and single-qubit gates, with an
+ *  implicit swap.
+ */
+Circuit TK2_using_ISWAPMax_and_swap(
+    const Expr &alpha, const Expr &beta, const Expr &gamma);
+
 /** Equivalent to XXPhase3, using three TK2 gates */
 Circuit XXPhase3_using_TK2(const Expr &alpha);
 

tket/src/Circuit/CircPool.cpp

@@ -105,6 +105,34 @@ const Circuit &CX_using_ZZMax() {
   return *C;
 }
 
+const Circuit &CX_using_ISWAPMax() {
+  static std::unique_ptr<const Circuit> C = std::make_unique<Circuit>([]() {
+    Circuit c(2);
+    c.add_op<unsigned>(OpType::ISWAPMax, {0, 1});
+    c.add_op<unsigned>(OpType::H, {0});
+    c.add_op<unsigned>(OpType::ISWAPMax, {0, 1});
+    c.add_op<unsigned>(OpType::Sdg, {0});
+    c.add_op<unsigned>(OpType::V, {1});
+    return c;
+  }());
+  return *C;
+}
+
+const Circuit &CX_using_ISWAPMax_and_swap() {
+  static std::unique_ptr<const Circuit> C = std::make_unique<Circuit>([]() {
+    Circuit c(2);
+    c.add_op<unsigned>(OpType::H, {1});
+    c.add_op<unsigned>(OpType::Sdg, {0});
+    c.add_op<unsigned>(OpType::Sdg, {1});
+    c.add_op<unsigned>(OpType::ISWAPMax, {0, 1});
+    c.add_op<unsigned>(OpType::H, {0});
+    c.add_op<unsigned>(OpType::SWAP, {0, 1});
+    c.replace_SWAPs();
+    return c;
+  }());
+  return *C;
+}
+
 const Circuit &CX_using_ZZPhase() {
   static std::unique_ptr<const Circuit> C = std::make_unique<Circuit>([]() {
     Circuit c(2);
@@ -684,6 +712,31 @@ const Circuit &ZZMax_using_CX() {
   return *C;
 }
 
+const Circuit &ISWAPMax_using_TK2() {
+  static std::unique_ptr<const Circuit> C = std::make_unique<Circuit>([]() {
+    Circuit c(2);
+    c.add_op<unsigned>(OpType::TK2, {-0.5, -0.5, 0}, {0, 1});
+    return c;
+  }());
+  return *C;
+}
+
+const Circuit &ISWAPMax_using_CX() {
+  static std::unique_ptr<const Circuit> C = std::make_unique<Circuit>([]() {
+    Circuit c(2);
+    c.add_op<unsigned>(OpType::U3, {0.5, -0.5, 0.5}, {0});
+    c.add_op<unsigned>(OpType::U3, {0.5, -0.5, 0.5}, {1});
+    c.add_op<unsigned>(OpType::CX, {0, 1});
+    c.add_op<unsigned>(OpType::U3, {-0.5, -0.5, 0.5}, {0});
+    c.add_op<unsigned>(OpType::Rz, -0.5, {1});
+    c.add_op<unsigned>(OpType::CX, {0, 1});
+    c.add_op<unsigned>(OpType::U3, {-0.5, -0.5, 0.5}, {0});
+    c.add_op<unsigned>(OpType::U3, {-0.5, -0.5, 0.5}, {1});
+    return c;
+  }());
+  return *C;
+}
+
 Circuit CRz_using_TK2(const Expr &alpha) {
   Circuit c(2);
   c.add_op<unsigned>(OpType::TK1, {0.5, 0.5, 1}, {0});
@@ -1116,6 +1169,41 @@ Circuit TK2_using_ZZMax_and_swap(
   return TK2_using_ZZMax(alpha, beta, gamma);
 }
 
+Circuit TK2_using_ISWAPMax(
+    const Expr &alpha, const Expr &beta, const Expr &gamma) {
+  Circuit c = TK2_using_CX(alpha, beta, gamma);
+  // Find the CX gates and replace them with ISWAPMax.
+  VertexSet bin;
+  BGL_FORALL_VERTICES(v, c.dag, DAG) {
+    Op_ptr op = c.get_Op_ptr_from_Vertex(v);
+    if (op->get_type() == OpType::CX) {
+      c.substitute(CX_using_ISWAPMax(), v, Circuit::VertexDeletion::No);
+      bin.insert(v);
+    }
+  }
+  c.remove_vertices(
+      bin, Circuit::GraphRewiring::No, Circuit::VertexDeletion::Yes);
+  return c;
+}
+
+Circuit TK2_using_ISWAPMax_and_swap(
+    const Expr &alpha, const Expr &beta, const Expr &gamma) {
+  Circuit c = TK2_using_CX_and_swap(alpha, beta, gamma);
+  // Find the CX gates and replace them with ISWAPMax.
+  VertexSet bin;
+  BGL_FORALL_VERTICES(v, c.dag, DAG) {
+    Op_ptr op = c.get_Op_ptr_from_Vertex(v);
+    if (op->get_type() == OpType::CX) {
+      c.substitute(
+          CX_using_ISWAPMax_and_swap(), v, Circuit::VertexDeletion::No);
+      bin.insert(v);
+    }
+  }
+  c.remove_vertices(
+      bin, Circuit::GraphRewiring::No, Circuit::VertexDeletion::Yes);
+  return c;
+}
+
 Circuit XXPhase3_using_TK2(const Expr &alpha) {
   Circuit c(3);
   c.add_op<unsigned>(OpType::TK2, {alpha, 0, 0}, {0, 1});

tket/src/Circuit/CircUtils.cpp

@@ -475,6 +475,8 @@ Circuit with_TK2(Gate_ptr op) {
   switch (op->get_type()) {
     case OpType::ISWAP:
       return CircPool::ISWAP_using_TK2(params[0]);
+    case OpType::ISWAPMax:
+      return CircPool::ISWAPMax_using_TK2();
     case OpType::PhasedISWAP:
       return CircPool::PhasedISWAP_using_TK2(params[0], params[1]);
     case OpType::XXPhase:
@@ -603,7 +605,7 @@ Circuit with_CX(Gate_ptr op) {
     case OpType::Sycamore:
       return CircPool::FSim_using_CX(1. / 2., 1. / 6.);
     case OpType::ISWAPMax:
-      return CircPool::ISWAP_using_CX(1.);
+      return CircPool::ISWAPMax_using_CX();
     case OpType::PhasedISWAP:
       return CircPool::PhasedISWAP_using_CX(params[0], params[1]);
     case OpType::NPhasedX: