Merge branch 'main' into qgf_add_k

Author: tanujkhattar

qualtran/_infra/binst_graph_iterators.py

@@ -40,6 +40,8 @@ def _priority(node: 'BloqInstance') -> int:
         return -_ALLOCATION_PRIORITY
 
     signature = node.bloq.signature
+    if any(reg.dtype.is_symbolic() for reg in signature):
+        return 0
     return total_bits(signature.rights()) - total_bits(signature.lefts())
 
 

qualtran/_infra/binst_graph_iterators_test.py

@@ -11,7 +11,7 @@
 #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
-
+import sympy
 from attrs import frozen
 
 from qualtran import (
@@ -26,7 +26,7 @@
     SoquetT,
 )
 from qualtran._infra.binst_graph_iterators import greedy_topological_sort
-from qualtran.bloqs.basic_gates import CNOT
+from qualtran.bloqs.basic_gates import CNOT, IntState, Swap
 from qualtran.bloqs.bookkeeping import Allocate, Free
 
 
@@ -61,3 +61,24 @@ def test_greedy_topological_sort():
         BloqInstance(bloq=Free(dtype=QBit()), i=5),
         RightDangle,
     ]
+
+
+def test_topo_sort_with_symbolic_registers():
+    # when _priority returns a symbolic value, networkx will try to use
+    # it in a comparison and you would get
+    # TypeError: cannot determine truth value of Relational.
+
+    n = sympy.Symbol('n')
+    bb = BloqBuilder()
+
+    # This isn't usually a problem for thru-registers since sympy will
+    # simplify n-n to zero, which can be compared. Test against a sided
+    # symbolic register
+    x = bb.add(IntState(5, n))
+
+    y = bb.add_register('y', n)
+    x, y = bb.add(Swap(n), x=x, y=y)
+    x, y = bb.add(Swap(n), x=x, y=y)
+    cbloq = bb.finalize(x=x, y=y)
+    res = list(greedy_topological_sort(cbloq._binst_graph))
+    assert len(res) > 0

qualtran/_infra/composite_bloq.py

@@ -53,6 +53,7 @@
     from qualtran.cirq_interop._cirq_to_bloq import CirqQuregInT, CirqQuregT
     from qualtran.resource_counting import BloqCountDictT, SympySymbolAllocator
     from qualtran.simulation.classical_sim import ClassicalValT
+    from qualtran.symbolics import SymbolicInt
 
 # NDArrays must be bound to np.generic
 _SoquetType = TypeVar('_SoquetType', bound=np.generic)
@@ -883,10 +884,10 @@ def add_register_from_dtype(
     def add_register(self, reg: Register, bitsize: None = None) -> Union[None, SoquetT]: ...
 
     @overload
-    def add_register(self, reg: str, bitsize: int) -> SoquetT: ...
+    def add_register(self, reg: str, bitsize: 'SymbolicInt') -> SoquetT: ...
 
     def add_register(
-        self, reg: Union[str, Register], bitsize: Optional[int] = None
+        self, reg: Union[str, Register], bitsize: Optional['SymbolicInt'] = None
     ) -> Union[None, SoquetT]:
         """Add a new register to the composite bloq being built.