Merge pull request #190 from CQCL/release/0.20

Release/0.20

_metadata.py

@@ -1,2 +1,2 @@
-__extension_version__ = "0.19.0"
+__extension_version__ = "0.20.0"
 __extension_name__ = "pytket-quantinuum"

docs/changelog.rst

@@ -1,6 +1,18 @@
 Changelog
 ~~~~~~~~~
 
+0.20.0 (August 2023)
+--------------------
+
+* Update pytket version requirement to 1.18.
+* Add ``implicit_swaps`` option to 
+  ``QuantinuumBackend.rebase_pass``, which 
+  can use implicit wire swaps (represented in the circuit qubit permutation)
+  to help implement some gates when chosen. Defaults to ``False``.
+* Add  ``implicit_swaps`` option to 
+  ``QuantinuumBackend.default_compilation_pass``, which 
+  is used in the rebase step. Defaults to ``True``.
+
 0.19.0 (August 2023)
 --------------------
 

pytket/extensions/quantinuum/backends/quantinuum.py

@@ -372,10 +372,32 @@ def required_predicates(self) -> List[Predicate]:
 
         return preds
 
-    def rebase_pass(self) -> BasePass:
-        return auto_rebase_pass(self._gate_set)
+    def rebase_pass(self, implicit_swaps: bool = False) -> BasePass:
+        """
+        :param implicit_swaps: If true, allows rebasing of Circuit via TK2 gates
+            to use implicit wire swaps in circuit construction if it reduces
+            the total 2qb qate count.
+        :type implicit_swaps: bool
+        :return: Compilation pass for rebasing circuits
+        :rtype: BasePass
+        """
+        return auto_rebase_pass(self._gate_set, implicit_swaps)
 
-    def default_compilation_pass(self, optimisation_level: int = 2) -> BasePass:
+    def default_compilation_pass(
+        self, optimisation_level: int = 2, implicit_swaps: bool = True
+    ) -> BasePass:
+        """
+        :param optimisation_level: Allows values of 0,1 or 2, with higher values
+            prompting more computationally heavy optimising compilation that
+            can lead to reduced gate count in circuits.
+        :type optimisation_level: int
+        :param implicit_swaps: If true, allows rebasing of Circuit via TK2 gates
+            to use implicit wire swaps in circuit construction if it reduces
+            the total 2qb qate count.
+        :type implicit_swaps: bool
+        :return: Compilation pass for compiling circuits to Quantinuum devices
+        :rtype: BasePass
+        """
         assert optimisation_level in range(3)
         passlist = [
             DecomposeBoxes(),
@@ -399,14 +421,14 @@ def default_compilation_pass(self, optimisation_level: int = 2) -> BasePass:
         # https://cqcl.github.io/pytket-quantinuum/api/index.html#default-compilation
         # Edit this docs source file -> pytket-quantinuum/docs/intro.txt
         if optimisation_level == 0:
-            passlist.append(self.rebase_pass())
+            passlist.append(self.rebase_pass(implicit_swaps=implicit_swaps))
         elif optimisation_level == 1:
             passlist.extend(
                 [
                     SynthesiseTK(),
                     NormaliseTK2(),
                     DecomposeTK2(**fidelities),
-                    self.rebase_pass(),
+                    self.rebase_pass(implicit_swaps=implicit_swaps),
                     ZZPhaseToRz(),
                     RemoveRedundancies(),
                     squash,
@@ -421,7 +443,7 @@ def default_compilation_pass(self, optimisation_level: int = 2) -> BasePass:
                     FullPeepholeOptimise(target_2qb_gate=OpType.TK2),
                     NormaliseTK2(),
                     DecomposeTK2(**fidelities),
-                    self.rebase_pass(),
+                    self.rebase_pass(implicit_swaps=implicit_swaps),
                     RemoveRedundancies(),
                     squash,
                     SimplifyInitial(

setup.py

@@ -43,7 +43,7 @@
     packages=find_namespace_packages(include=["pytket.*"]),
     include_package_data=True,
     install_requires=[
-        "pytket ~= 1.17",
+        "pytket ~= 1.18",
         "requests >= 2.2",
         "types-requests",
         "websockets >= 7.0",

tests/unit/convert_test.py

@@ -14,7 +14,7 @@
 
 import pytest
 
-from pytket.circuit import Circuit, OpType, reg_eq  # type: ignore
+from pytket.circuit import Circuit, OpType, Qubit, reg_eq  # type: ignore
 from pytket._tket.circuit import _TEMP_BIT_NAME, _TEMP_BIT_REG_BASE  # type: ignore
 from pytket.extensions.quantinuum import QuantinuumBackend
 from pytket.extensions.quantinuum.backends.quantinuum import scratch_reg_resize_pass
@@ -29,7 +29,7 @@ def test_convert() -> None:
     circ.add_barrier([2])
     circ.measure_all()
 
-    QuantinuumBackend("", machine_debug=True).rebase_pass().apply(circ)
+    QuantinuumBackend("", machine_debug=True).rebase_pass(False).apply(circ)
     circ_quum = circuit_to_qasm_str(circ, header="hqslib1")
     qasm_str = circ_quum.split("\n")[6:-1]
     assert all(
@@ -46,7 +46,7 @@ def test_convert_rzz() -> None:
     circ.add_gate(OpType.ZZMax, [2, 3])
     circ.measure_all()
 
-    QuantinuumBackend("", machine_debug=True).rebase_pass().apply(circ)
+    QuantinuumBackend("", machine_debug=True).rebase_pass(False).apply(circ)
     circ_quum = circuit_to_qasm_str(circ, header="hqslib1")
     qasm_str = circ_quum.split("\n")[6:-1]
     assert all(
@@ -121,3 +121,80 @@ def test_resize_scratch_registers() -> None:
     c_compiled = circ.copy()
     scratch_reg_resize_pass(10).apply(c_compiled)
     assert circ == c_compiled
+
+
+def test_implicit_swap_removal() -> None:
+    b = QuantinuumBackend("", machine_debug=True)
+    c = Circuit(2).ISWAPMax(0, 1)
+    compiled = b.get_compiled_circuit(c, 0)
+    assert compiled.n_gates_of_type(OpType.ZZMax) == 1
+    assert compiled.n_gates_of_type(OpType.ZZPhase) == 0
+    iqp = compiled.implicit_qubit_permutation()
+    assert iqp[Qubit(0)] == Qubit(1)
+    assert iqp[Qubit(1)] == Qubit(0)
+    c = Circuit(2).ISWAPMax(0, 1)
+    b.rebase_pass(False).apply(c)
+    assert c.n_gates_of_type(OpType.ZZMax) == 2
+    assert c.n_gates_of_type(OpType.ZZPhase) == 0
+
+    c = Circuit(2).Sycamore(0, 1)
+    compiled = b.get_compiled_circuit(c, 0)
+    assert compiled.n_gates_of_type(OpType.ZZMax) == 2
+    assert compiled.n_gates_of_type(OpType.ZZPhase) == 0
+    iqp = compiled.implicit_qubit_permutation()
+    assert iqp[Qubit(0)] == Qubit(1)
+    assert iqp[Qubit(1)] == Qubit(0)
+    c = Circuit(2).Sycamore(0, 1)
+    b.rebase_pass(False).apply(c)
+    assert c.n_gates_of_type(OpType.ZZMax) == 3
+    assert c.n_gates_of_type(OpType.ZZPhase) == 0
+
+    c = Circuit(2).ISWAP(0.3, 0, 1)
+    compiled = b.get_compiled_circuit(c, 0)
+    assert compiled.n_gates_of_type(OpType.ZZMax) == 2
+    assert compiled.n_gates_of_type(OpType.ZZPhase) == 0
+    iqp = compiled.implicit_qubit_permutation()
+    assert iqp[Qubit(0)] == Qubit(0)
+    assert iqp[Qubit(1)] == Qubit(1)
+    c = Circuit(2).ISWAP(0.3, 0, 1)
+    b.rebase_pass(False).apply(c)
+    assert c.n_gates_of_type(OpType.ZZMax) == 2
+    assert c.n_gates_of_type(OpType.ZZPhase) == 0
+
+    c = Circuit(2).ISWAPMax(0, 1).ISWAPMax(1, 0)
+    compiled = b.get_compiled_circuit(c, 0)
+    assert compiled.n_gates_of_type(OpType.ZZMax) == 2
+    assert compiled.n_gates_of_type(OpType.ZZPhase) == 0
+    iqp = compiled.implicit_qubit_permutation()
+    assert iqp[Qubit(0)] == Qubit(0)
+    assert iqp[Qubit(1)] == Qubit(1)
+    c = Circuit(2).ISWAPMax(0, 1).ISWAPMax(1, 0)
+    compiled = b.get_compiled_circuit(c, 1)
+    assert compiled.n_gates_of_type(OpType.ZZMax) == 0
+    assert compiled.n_gates_of_type(OpType.ZZPhase) == 0
+    iqp = compiled.implicit_qubit_permutation()
+    assert iqp[Qubit(0)] == Qubit(0)
+    c = Circuit(2).ISWAPMax(0, 1).ISWAPMax(1, 0)
+    b.rebase_pass(False).apply(c)
+    assert c.n_gates_of_type(OpType.ZZMax) == 4
+    assert c.n_gates_of_type(OpType.ZZPhase) == 0
+
+    c = Circuit(2).SWAP(0, 1)
+    compiled = b.get_compiled_circuit(c, 0)
+    assert compiled.n_gates_of_type(OpType.ZZMax) == 0
+    assert compiled.n_gates_of_type(OpType.ZZPhase) == 0
+    iqp = compiled.implicit_qubit_permutation()
+    assert iqp[Qubit(0)] == Qubit(1)
+    assert iqp[Qubit(1)] == Qubit(0)
+    c = Circuit(2).SWAP(0, 1)
+    b.rebase_pass(False).apply(c)
+    assert c.n_gates_of_type(OpType.ZZMax) == 3
+    assert c.n_gates_of_type(OpType.ZZPhase) == 0
+
+    c = Circuit(2).ZZMax(0, 1)
+    compiled = b.get_compiled_circuit(c, 0)
+    assert compiled.n_gates == 1
+
+
+if __name__ == "__main__":
+    test_implicit_swap_removal()