Deprecate cirq.ConvertToSqrtIswapGates and cirq.MergeInteractionsToSq…

…rtIswap (quantumlib#5040)

cirq-core/cirq/optimizers/merge_interactions.py

@@ -26,6 +26,10 @@
     import cirq
 
 
+@_compat.deprecated_class(
+    deadline='v1.0',
+    fix='Use cirq.optimize_for_target_gateset and cirq.CompilationTargetGateset instead.',
+)
 class MergeInteractionsAbc(circuits.PointOptimizer, metaclass=abc.ABCMeta):
     """Combines series of adjacent one- and two-qubit, non-parametrized gates
     operating on a pair of qubits."""

cirq-core/cirq/optimizers/merge_interactions_test.py

@@ -22,7 +22,9 @@
 
 def assert_optimizes(before: cirq.Circuit, expected: cirq.Circuit):
     actual = cirq.Circuit(before)
-    with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset", deadline='v1.0'):
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
         opt = cirq.MergeInteractions()
     opt.optimize_circuit(actual)
 
@@ -46,7 +48,9 @@ def assert_optimization_not_broken(circuit):
     global phase and rounding error) as the unitary matrix of the optimized
     circuit."""
     u_before = circuit.unitary()
-    with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset", deadline='v1.0'):
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
         cirq.MergeInteractions().optimize_circuit(circuit)
     u_after = circuit.unitary()
 
@@ -161,7 +165,9 @@ def test_optimizes_single_iswap():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(cirq.ISWAP(a, b))
     assert_optimization_not_broken(c)
-    with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset", deadline='v1.0'):
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
         cirq.MergeInteractions().optimize_circuit(c)
     assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 2
 
@@ -170,7 +176,9 @@ def test_optimizes_tagged_partial_cz():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit((cirq.CZ ** 0.5)(a, b).with_tags('mytag'))
     assert_optimization_not_broken(c)
-    with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset", deadline='v1.0'):
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
         cirq.MergeInteractions(allow_partial_czs=False).optimize_circuit(c)
     assert (
         len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 2
@@ -182,7 +190,9 @@ def test_not_decompose_czs():
         cirq.CZPowGate(exponent=1, global_shift=-0.5).on(*cirq.LineQubit.range(2))
     )
     circ_orig = circuit.copy()
-    with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset", deadline='v1.0'):
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
         cirq.MergeInteractions(allow_partial_czs=False).optimize_circuit(circuit)
     assert circ_orig == circuit
 
@@ -200,7 +210,9 @@ def test_not_decompose_czs():
     ),
 )
 def test_decompose_partial_czs(circuit):
-    with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset", deadline='v1.0'):
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
         optimizer = cirq.MergeInteractions(allow_partial_czs=False)
     optimizer.optimize_circuit(circuit)
 
@@ -219,7 +231,9 @@ def test_not_decompose_partial_czs():
     circuit = cirq.Circuit(
         cirq.CZPowGate(exponent=0.1, global_shift=-0.5)(*cirq.LineQubit.range(2)),
     )
-    with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset", deadline='v1.0'):
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
         optimizer = cirq.MergeInteractions(allow_partial_czs=True)
     optimizer.optimize_circuit(circuit)
 
@@ -253,7 +267,9 @@ def clean_up(operations):
         yield operations
         yield Marker()(a, b)
 
-    with cirq.testing.assert_deprecated("Use cirq.optimize_for_target_gateset", deadline='v1.0'):
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
         optimizer = cirq.MergeInteractions(allow_partial_czs=False, post_clean_up=clean_up)
     optimizer.optimize_circuit(circuit)
     circuit = cirq.drop_empty_moments(circuit)

cirq-core/cirq/optimizers/merge_interactions_to_sqrt_iswap.py

@@ -19,14 +19,18 @@
 
 import numpy as np
 
-from cirq import ops
+from cirq import ops, _compat
 from cirq.optimizers import merge_interactions
 from cirq.transformers.analytical_decompositions import two_qubit_to_sqrt_iswap
 
 if TYPE_CHECKING:
     import cirq
 
 
+@_compat.deprecated_class(
+    deadline='v1.0',
+    fix='Use cirq.optimize_for_target_gateset and cirq.SqrtIswapTargetGateset instead.',
+)
 class MergeInteractionsToSqrtIswap(merge_interactions.MergeInteractionsAbc):
     """Combines series of adjacent one- and two-qubit, non-parametrized gates
     operating on a pair of qubits and replaces each series with the minimum

cirq-core/cirq/optimizers/merge_interactions_to_sqrt_iswap_test.py

@@ -33,8 +33,11 @@ def assert_optimizes(before: cirq.Circuit, expected: cirq.Circuit, **kwargs):
             ``MergeInteractionsToSqrtIswap`` constructor.
     """
     actual = before.copy()
-    opt = cirq.MergeInteractionsToSqrtIswap(**kwargs)
-    opt.optimize_circuit(actual)
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
+        opt = cirq.MergeInteractionsToSqrtIswap(**kwargs)
+        opt.optimize_circuit(actual)
 
     # Ignore differences that would be caught by follow-up optimizations.
     followup_transformers: List[cirq.TRANSFORMER] = [
@@ -57,15 +60,23 @@ def assert_optimization_not_broken(circuit: cirq.Circuit, **kwargs):
     circuit."""
     u_before = circuit.unitary(sorted(circuit.all_qubits()))
     c_sqrt_iswap = circuit.copy()
-    cirq.MergeInteractionsToSqrtIswap(**kwargs).optimize_circuit(c_sqrt_iswap)
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
+        cirq.MergeInteractionsToSqrtIswap(**kwargs).optimize_circuit(c_sqrt_iswap)
     u_after = c_sqrt_iswap.unitary(sorted(circuit.all_qubits()))
 
     # Not 1e-8 because of some unaccounted accumulated error in some of Cirq's linalg functions
     cirq.testing.assert_allclose_up_to_global_phase(u_before, u_after, atol=1e-6)
 
     # Also test optimization with SQRT_ISWAP_INV
     c_sqrt_iswap_inv = circuit.copy()
-    cirq.MergeInteractionsToSqrtIswap(use_sqrt_iswap_inv=True).optimize_circuit(c_sqrt_iswap_inv)
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
+        cirq.MergeInteractionsToSqrtIswap(use_sqrt_iswap_inv=True).optimize_circuit(
+            c_sqrt_iswap_inv
+        )
     u_after2 = c_sqrt_iswap_inv.unitary(sorted(circuit.all_qubits()))
 
     cirq.testing.assert_allclose_up_to_global_phase(u_before, u_after2, atol=1e-6)
@@ -230,79 +241,112 @@ def test_optimizes_single_iswap():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(cirq.ISWAP(a, b))
     assert_optimization_not_broken(c)
-    cirq.MergeInteractionsToSqrtIswap().optimize_circuit(c)
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
+        cirq.MergeInteractionsToSqrtIswap().optimize_circuit(c)
     assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 2
 
 
 def test_optimizes_single_inv_sqrt_iswap():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(cirq.SQRT_ISWAP_INV(a, b))
     assert_optimization_not_broken(c)
-    cirq.MergeInteractionsToSqrtIswap().optimize_circuit(c)
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
+        cirq.MergeInteractionsToSqrtIswap().optimize_circuit(c)
     assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 1
 
 
 def test_init_raises():
     with pytest.raises(ValueError, match='must be 0, 1, 2, or 3'):
-        cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=4)
+        with cirq.testing.assert_deprecated(
+            "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+        ):
+            cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=4)
 
 
 def test_optimizes_single_iswap_require0():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(cirq.CNOT(a, b), cirq.CNOT(a, b))  # Minimum 0 sqrt-iSWAP
     assert_optimization_not_broken(c, required_sqrt_iswap_count=0)
-    cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=0).optimize_circuit(c)
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
+        cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=0).optimize_circuit(c)
     assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 0
 
 
 def test_optimizes_single_iswap_require0_raises():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(cirq.CNOT(a, b))  # Minimum 2 sqrt-iSWAP
     with pytest.raises(ValueError, match='cannot be decomposed into exactly 0 sqrt-iSWAP gates'):
-        cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=0).optimize_circuit(c)
+        with cirq.testing.assert_deprecated(
+            "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+        ):
+            cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=0).optimize_circuit(c)
 
 
 def test_optimizes_single_iswap_require1():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(cirq.SQRT_ISWAP_INV(a, b))  # Minimum 1 sqrt-iSWAP
     assert_optimization_not_broken(c, required_sqrt_iswap_count=1)
-    cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=1).optimize_circuit(c)
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
+        cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=1).optimize_circuit(c)
     assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 1
 
 
 def test_optimizes_single_iswap_require1_raises():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(cirq.CNOT(a, b))  # Minimum 2 sqrt-iSWAP
     with pytest.raises(ValueError, match='cannot be decomposed into exactly 1 sqrt-iSWAP gates'):
-        cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=1).optimize_circuit(c)
+        with cirq.testing.assert_deprecated(
+            "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+        ):
+            cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=1).optimize_circuit(c)
 
 
 def test_optimizes_single_iswap_require2():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(cirq.SQRT_ISWAP_INV(a, b))  # Minimum 1 sqrt-iSWAP but 2 possible
     assert_optimization_not_broken(c, required_sqrt_iswap_count=2)
-    cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=2).optimize_circuit(c)
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
+        cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=2).optimize_circuit(c)
     assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 2
 
 
 def test_optimizes_single_iswap_require2_raises():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(cirq.SWAP(a, b))  # Minimum 3 sqrt-iSWAP
     with pytest.raises(ValueError, match='cannot be decomposed into exactly 2 sqrt-iSWAP gates'):
-        cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=2).optimize_circuit(c)
+        with cirq.testing.assert_deprecated(
+            "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+        ):
+            cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=2).optimize_circuit(c)
 
 
 def test_optimizes_single_iswap_require3():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(cirq.ISWAP(a, b))  # Minimum 2 sqrt-iSWAP but 3 possible
     assert_optimization_not_broken(c, required_sqrt_iswap_count=3)
-    cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=3).optimize_circuit(c)
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
+        cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=3).optimize_circuit(c)
     assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 3
 
 
 def test_optimizes_single_inv_sqrt_iswap_require3():
     a, b = cirq.LineQubit.range(2)
     c = cirq.Circuit(cirq.SQRT_ISWAP_INV(a, b))
     assert_optimization_not_broken(c, required_sqrt_iswap_count=3)
-    cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=3).optimize_circuit(c)
+    with cirq.testing.assert_deprecated(
+        "Use cirq.optimize_for_target_gateset", deadline='v1.0', count=2
+    ):
+        cirq.MergeInteractionsToSqrtIswap(required_sqrt_iswap_count=3).optimize_circuit(c)
     assert len([1 for op in c.all_operations() if len(op.qubits) == 2]) == 3

cirq-google/cirq_google/optimizers/convert_to_sqrt_iswap.py

@@ -29,6 +29,10 @@ def _near_mod_2pi(e, t, atol=1e-8):
     return _near_mod_n(e, t, 2 * np.pi, atol=atol)
 
 
+@cirq._compat.deprecated_class(
+    deadline='v1.0',
+    fix='Use cirq.optimize_for_target_gateset and cirq.SqrtIswapTargetGateset instead.',
+)
 class ConvertToSqrtIswapGates(cirq.PointOptimizer):
     """Attempts to convert gates into ISWAP**-0.5 gates.