Remove Phase operations when compiling for backends (#565)

Author: cqc-alec

docs/changelog.md

@@ -7,6 +7,7 @@
 ## Unreleased
 
 - Check for language support when submitting programs.
+- Remove all `Phase` operations from circuit when compiling for backend.
 
 ## 0.42.0 (December 2024)
 

pytket/extensions/quantinuum/backends/quantinuum.py

@@ -56,6 +56,7 @@
     GreedyPauliSimp,
     NormaliseTK2,
     RemoveBarriers,
+    RemovePhaseOps,
     RemoveRedundancies,
     SequencePass,
     SimplifyInitial,
@@ -785,6 +786,7 @@ def default_compilation_pass(
                     RemoveRedundancies(),
                 ]
             )
+        passlist.append(RemovePhaseOps())
 
         # In TKET, a qubit register with N qubits can have qubits
         # indexed with a a value greater than N, i.e. a single

setup.py

@@ -45,7 +45,7 @@
     packages=find_namespace_packages(include=["pytket.*"]),
     include_package_data=True,
     install_requires=[
-        "pytket >= 1.37.0",
+        "pytket >= 1.39.0",
         "pytket-qir >= 0.17, < 0.18",
         "requests >= 2.32.2",
         "types-requests",

tests/integration/backend_test.py

@@ -34,6 +34,7 @@
 from pytket.circuit import (
     Bit,
     Circuit,
+    Conditional,
     Node,
     OpType,
     Qubit,
@@ -1563,3 +1564,28 @@ def test_optimisation_level_3_compilation(
     assert compiled_3.n_2qb_gates() == 31
     assert compiled_3.n_gates == 93
     assert compiled_3.depth() == 49
+
+
+@pytest.mark.parametrize(
+    "authenticated_quum_backend_qa", [{"device_name": "H2-1E"}], indirect=True
+)
+def test_no_phase_ops(authenticated_quum_backend_qa: QuantinuumBackend) -> None:
+    b = authenticated_quum_backend_qa
+
+    c = (
+        Circuit(3, 3)
+        .H(0)
+        .Measure(0, 0)
+        .H(1)
+        .CX(1, 2, condition_bits=[0], condition_value=1)
+        .Measure(1, 1)
+        .Measure(2, 2)
+    )
+    c1 = b.get_compiled_circuit(c)
+    for cmd in c1.get_commands():
+        op = cmd.op
+        typ = op.type
+        assert typ != OpType.Phase
+        if typ == OpType.Conditional:
+            assert isinstance(op, Conditional)
+            assert op.op.type != OpType.Phase